101
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Affiliation(s)
- Wataru Mizunoya
- Department of Bioresource Sciences, Faculty of Agriculture, Kyushu University
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102
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Sinthupoom N, Prachayasittikul V, Prachayasittikul S, Ruchirawat S, Prachayasittikul V. Nicotinic acid and derivatives as multifunctional pharmacophores for medical applications. Eur Food Res Technol 2014. [DOI: 10.1007/s00217-014-2354-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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103
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Koh Y, Bidstrup H, Nichols DL. Niacin increased glucose, insulin, and C-peptide levels in sedentary nondiabetic postmenopausal women. Int J Womens Health 2014; 6:913-20. [PMID: 25364276 PMCID: PMC4211901 DOI: 10.2147/ijwh.s69908] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
The current study examined the effects of niacin and a single bout of aerobic exercise on plasma glucose, insulin, and C-peptide in sedentary, nondiabetic postmenopausal women. As a crossover design, 17 participants underwent four different trials: rest during the no-niacin condition (R), exercise during the no-niacin condition (E), rest during the with-niacin condition (RN), and exercise during the with-niacin condition (EN). All participants took 1,000 mg/day of extended-release niacin for 4 weeks during the with-niacin conditions (RN and EN). The exercise treatment consisted of a single bout of treadmill walking at 60% heart rate reserve until 400 kcal were expended. Blood samples were collected at 24 hours after each trial and analyzed for changes in plasma glucose, insulin, and C-peptide. A two by two analysis of variance was used to examine the changes in dependent variables, and the Bonferroni adjustment was employed as the post hoc test. The level of statistical significance was set at P<0.05. There was no significant interaction between exercise and niacin, nor was there a main effect of exercise for changes in glucose, insulin, or C-peptide. However, there was a significant main effect for niacin as mean glucose, insulin, and C-peptide values significantly increased with niacin; glucose increased 10.6% (P=0.001), from 95.03±10.67 mg/dL to 105.07±13.56 mg/dL; insulin increased 61.8% (P=0.001), from 16.98±12.49 μU/mL to 27.48±14.84 μU/mL; and C-peptide increased 46.1% (P=0.001), from 1.65±0.75 ng/mL to 2.41±0.97 ng/mL. Although niacin was generally well tolerated, given its adverse effects on glucose, insulin, and C-peptide profiles, the use of niacin should be done so with caution and under medical supervision.
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Affiliation(s)
- Yunsuk Koh
- Department of Health, Human Performance, and Recreation, Baylor University, Waco, TX, USA
| | - Heidi Bidstrup
- Department of Kinesiology, Texas Woman's University, Denton, TX, USA
| | - David L Nichols
- Department of Kinesiology, Texas Woman's University, Denton, TX, USA
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104
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Wakade C, Chong R, Bradley E, Thomas B, Morgan J. Upregulation of GPR109A in Parkinson's disease. PLoS One 2014; 9:e109818. [PMID: 25329911 PMCID: PMC4201464 DOI: 10.1371/journal.pone.0109818] [Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2014] [Accepted: 09/04/2014] [Indexed: 01/01/2023] Open
Abstract
BACKGROUND Anecdotal animal and human studies have implicated the symptomatic and neuroprotective roles of niacin in Parkinson's disease (PD). Niacin has a high affinity for GPR109A, an anti-inflammatory receptor. Niacin is also thought to be involved in the regulation of circadian rhythm. Here we evaluated the relationships among the receptor, niacin levels and EEG night-sleep in individuals with PD. METHODS AND FINDINGS GPR109A expression (blood and brain), niacin index (NAD-NADP ratio) and cytokine markers (blood) were analyzed. Measures of night-sleep function (EEG) and perceived sleep quality (questionnaire) were assessed. We observed significant up-regulation of GPR109A expression in the blood as well as in the substantia nigra (SN) in the PD group compared to age-matched controls. Confocal microscopy demonstrated co-localization of GPR109A staining with microglia in PD SN. Pro and anti-inflammatory cytokines did not show significant differences between the groups; however IL1-β, IL-4 and IL-7 showed an upward trend in PD. Time to sleep (sleep latency), EEG REM and sleep efficiency were different between PD and age-matched controls. Niacin levels were lower in PD and were associated with increased frequency of experiencing body pain and decreased duration of deep sleep. CONCLUSIONS The findings of associations among the GPR109A receptor, niacin levels and night-sleep function in individuals with PD are novel. Further studies are needed to understand the pathophysiological mechanisms of action of niacin, GPR109A expression and their associations with night-sleep function. It would be also crucial to study GPR109A expression in neurons, astrocytes, and microglia in PD. A clinical trial to determine the symptomatic and/or neuroprotective effect of niacin supplementation is warranted.
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Affiliation(s)
- Chandramohan Wakade
- Department of Physical Therapy, Georgia Regents University, Augusta, Georgia, United States of America
| | - Raymond Chong
- Department of Physical Therapy, Georgia Regents University, Augusta, Georgia, United States of America
| | - Eric Bradley
- Department of Physical Therapy, Georgia Regents University, Augusta, Georgia, United States of America
| | - Bobby Thomas
- Department of Pharmacology & Toxicology and Neurology, Georgia Regents University, Augusta, Georgia, United States of America
| | - John Morgan
- Department of Neurology, Georgia Regents University, Augusta, Georgia, United States of America
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105
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Ding Y, Li Y, Wen A. Effect of niacin on lipids and glucose in patients with type 2 diabetes: A meta-analysis of randomized, controlled clinical trials. Clin Nutr 2014; 34:838-44. [PMID: 25306426 DOI: 10.1016/j.clnu.2014.09.019] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2014] [Revised: 09/16/2014] [Accepted: 09/18/2014] [Indexed: 12/20/2022]
Abstract
BACKGROUND & AIMS This study aims to conduct a meta-analysis to evaluate the effects of niacin on serum lipids and glucose in patients with type 2 diabetes mellitus (T2DM). METHODS A comprehensive literature search in Medline, Scopus, AMED, Cochrane and Clinical trial registry databases was performed to identify randomized controlled trials investigating the effect of niacin on serum HDL cholesterol (HDL-c), LDL cholesterol (LDL-c), triglycerides (TG) and fasting plasma glucose (FPG). Pooled effects were measured by weighted mean difference (WMD) using fixed-effects or random-effects models. Quality assessment, and subgroup, meta-regression and sensitivity analyses were conducted using standard methods. Inter-study heterogeneity was assessed and quantified. RESULTS The estimated pooled mean changes (95% confidence interval) with niacin were 0.27 (95% CI: 0.24 to 0.30; P < 0.001) mmol/L for HDL-c, -0.250 (95% CI: -0.47 to -0.03; P < 0.05) mmol/L for LDL-c and -0.39 (95% CI: -0.43 to -0.34; P < 0.001) mmol/L for TG compared with controls. There was a significant heterogeneity for the impact of niacin on LDL-c and FPG. Subgroup analyses revealed a significant increase in FPG 0.085 (95% CI: 0.029 to 0.141; P < 0.05) mmol/L compared with controls in patients with long term treatment. Our analysis also showed the absence of publication bias and any dose-response relations between niacin and effect size. CONCLUSIONS Analysis of the results showed that niacin alone or in combination significantly improved lipid abnormalities in patients with TDM, but requires monitoring of glucose in long term treatment.
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Affiliation(s)
- Yi Ding
- Department of Pharmacy, Xijing Hospital, The Fourth Military Medical University, Xi'an, Shaanxi, China
| | - YuWen Li
- Department of Pharmacy, Xijing Hospital, The Fourth Military Medical University, Xi'an, Shaanxi, China.
| | - AiDong Wen
- Department of Pharmacy, Xijing Hospital, The Fourth Military Medical University, Xi'an, Shaanxi, China.
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106
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Li J, Li Y, Zhang P, Niu H, Shi Y. Nicotinic acid modulates intracellular calcium concentration and disassembles the cytoskeleton. Mol Med Rep 2014; 10:2805-10. [PMID: 25241762 PMCID: PMC4227433 DOI: 10.3892/mmr.2014.2576] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2013] [Accepted: 05/19/2014] [Indexed: 11/16/2022] Open
Abstract
Nicotinic acid (NA), a member of the vitamin B family, is well known for its functions in the treatment and prevention of atherosclerosis due to decreasing plasma levels of low-density lipoprotein cholesterol. In recent years, the major side effect of NA, cutaneous flushing, has also attracted extensive attention. However, the effects of NA in other aspects of physiology or cell biology have remained elusive. The present study provided evidence that high concentrations of NA were able to first reduce and later elevate intracellular [Ca2+] in the NIH3T3 cell line. The reduction of the intracellular Ca2+ concentration was achieved within the initial 10 sec, and was preceded by a gradual elevation of intracellular [Ca2+]. Notably, marked accumulation of opaque materials in the perinuclear region was observed in NIH3T3 cells treated with 70 mM NA. Further analysis revealed that treatment with 70 mM NA for 1 h disassembled the microtubule and F-actin cytoskeleton systems and resulted in β-tubulin degradation in an ubiquitin-proteasome-dependent manner. These data indicated that high concentrations of NA disrupted cytoskeleton structures, which may have contributed to minus end (nucleus region) to plus end (cell membrane region)-directed transport processes and resulted in the deposition of material in the perinuclear region. Artificially increasing [Ca2+] adding CaCl2 to the culture media effected the disassembly of F-actin, while it had no apparent effect on microtubules. These results suggested that the disruption of the cytoskeleton systems was not entirely due to the NA-induced elevation of [Ca2+]. Finally, microinjection of NA into xenopus embryos blocked the transport of melanosomes to the peripheral cellular area. In conclusion, the present study indicated that NA disassembles F-actin and microtubule systems, thereby blocking cytoskeleton-dependent intracellular transport.
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Affiliation(s)
- Jiejing Li
- Department of Clinical Laboratory, Children's Hospital of Chongqing Medical University, Chongqing 400014, P.R. China
| | - Yanxi Li
- Laboratory of Developmental Diseases in Childhood of Education Ministry, Key Laboratory of Pediatrics in Chongqing, Chongqing International Science and Technology Cooperation Center for Child Development and Disorder, Children's Hospital of Chongqing Medical University, Chongqing 400014, P.R. China
| | - Penghui Zhang
- Department of Clinical Laboratory, Children's Hospital of Chongqing Medical University, Chongqing 400014, P.R. China
| | - Hua Niu
- Clinical Laboratory Centre, The First People's Hospital of Yunnan Province, Kunming, Yunnan 650032, P.R. China
| | - Yu Shi
- Department of Clinical Laboratory, Children's Hospital of Chongqing Medical University, Chongqing 400014, P.R. China
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107
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Tiwari V, Khokhar M. Mechanism of action of anti-hypercholesterolemia drugs and their resistance. Eur J Pharmacol 2014; 741:156-70. [PMID: 25151024 DOI: 10.1016/j.ejphar.2014.07.048] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2014] [Revised: 07/23/2014] [Accepted: 07/24/2014] [Indexed: 01/05/2023]
Abstract
Coronary artery disease is one of the leading causes of death worldwide. One of the significant causes of this disease is hypercholesterolemia which is the result of various genetic alterations that are associated with the accumulation of specific classes of lipoprotein particles in plasma. A number of drugs are used to treat hypercholesterolemia like statin, fibrate, bile acid sequestrants, niacin, ezetimibe, omega-3 fatty acids and natural extracts. It has been observed that these drugs show diverse response in different individuals. The present review explains the mechanism of action of these drugs as well as mechanism of its lesser effectiveness or resistance in some individuals. There are various identified genetic variations that are associated with diversity in the drugs response. Therefore, present study helps to understand the ethiology of drug mechanism and resistance developed against drugs used to treat hypercholesterolemia.
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Affiliation(s)
- Vishvanath Tiwari
- Department of Biochemistry, Central University of Rajasthan, Ajmer 305801, Rajasthan, India.
| | - Manoj Khokhar
- Department of Biochemistry, Central University of Rajasthan, Ajmer 305801, Rajasthan, India
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108
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Couturier A, Ringseis R, Most E, Eder K. Pharmacological doses of niacin stimulate the expression of genes involved in carnitine uptake and biosynthesis and improve the carnitine status of obese Zucker rats. BMC Pharmacol Toxicol 2014; 15:37. [PMID: 25012467 PMCID: PMC4094635 DOI: 10.1186/2050-6511-15-37] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2014] [Accepted: 07/01/2014] [Indexed: 01/21/2023] Open
Abstract
Background Activation of peroxisome proliferator-activated receptor (PPAR)α and PPARδ causes an elevation of tissue carnitine concentrations through induction of genes involved in carnitine uptake [novel organic cation transporter 2, (OCTN2)], and carnitine biosynthesis [γ-butyrobetaine dioxygenase (BBD), 4-N-trimethyl-aminobutyraldehyde dehydrogenase (TMABA-DH)]. Recent studies showed that administration of the plasma lipid-lowering drug niacin causes activation of PPARα and/or PPARδ in tissues of obese Zucker rats, which have a compromised carnitine status and an impaired fatty acid oxidation capacity. Thus, we hypothesized that niacin administration to obese Zucker rats is also able to improve the diminished carnitine status of obese Zucker rats through PPAR-mediated stimulation of genes involved in carnitine uptake and biosynthesis. Methods To test this hypothesis, we used plasma, muscle and liver samples from a recent experiment with obese Zucker rats, which were fed either a niacin-adequate diet (30 mg niacin/kg diet) or a diet with a pharmacological niacin dose (780 mg niacin/kg diet), and determined concentrations of carnitine in tissues and mRNA and protein levels of genes critical for carnitine homeostasis (OCTN2, BBD, TMABA-DH). Statistical data analysis of all data was done by one-way ANOVA, and Fisher’s multiple range test. Results Rats of the obese niacin group had higher concentrations of total carnitine in plasma, skeletal muscle and liver, higher mRNA and protein levels of OCTN2, BBD, and TMABA-DH in the liver and higher mRNA and protein levels of OCTN2 in skeletal muscle than those of the obese control group (P < 0.05), whereas rats of the obese control group had lower concentrations of total carnitine in plasma and skeletal muscle than lean rats (P < 0.05). Conclusion The results show for the first time that niacin administration stimulates the expression of genes involved in carnitine uptake and biosynthesis and improves the diminished carnitine status of obese Zucker rats. We assume that the induction of genes involved in carnitine uptake and biosynthesis by niacin administration is mediated by PPAR-activation.
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Affiliation(s)
| | - Robert Ringseis
- Institute of Animal Nutrition and Nutrition Physiology, Justus-Liebig-University Giessen, Heinrich-Buff-Ring 26-32, 35390 Giessen, Germany.
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109
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Bobileva O, Bokaldere R, Gailite V, Kaula I, Ikaunieks M, Duburs G, Petrovska R, Mandrika I, Klovins J, Loza E. Synthesis and evaluation of (E)-2-(acrylamido)cyclohex-1-enecarboxylic acid derivatives as HCA1, HCA2, and HCA3 receptor agonists. Bioorg Med Chem 2014; 22:3654-69. [DOI: 10.1016/j.bmc.2014.05.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2013] [Revised: 04/15/2014] [Accepted: 05/09/2014] [Indexed: 12/23/2022]
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110
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Rungruang S, Collier JL, Rhoads RP, Baumgard LH, de Veth MJ, Collier RJ. A dose-response evaluation of rumen-protected niacin in thermoneutral or heat-stressed lactating Holstein cows. J Dairy Sci 2014; 97:5023-34. [PMID: 24881789 DOI: 10.3168/jds.2013-6970] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2013] [Accepted: 04/12/2014] [Indexed: 11/19/2022]
Abstract
Twenty-four multiparous high-producing dairy cows (40.0±1.4kg/d) were used in a factorial design to evaluate effects of 2 environments [thermoneutral (TN) and heat stress (HS)] and a dose range of dietary rumen-protected niacin (RPN; 0, 4, 8, or 12g/d) on body temperature, sweating rate, feed intake, water intake, production parameters, and blood niacin concentrations. Temperature-humidity index values during TN never exceeded 68 (stress threshold), whereas temperature-humidity index values during HS were above 68 for 24h/d. The HS environment increased hair coat and skin, rectal, and vaginal temperatures; respiration rate; skin and hair coat evaporative heat loss; and water intake and decreased DMI (3.5kg/d), milk yield (4.1kg/d), 4% fat-corrected milk (2.7kg/d), and milk protein yield (181.7g/d). Sweating rate increased during HS (12.7g/m(2) per h) compared with TN, but this increase was only 10% of that reported in summer-acclimated cattle. Niacin supplementation did not affect sweating rate, dry-matter intake, or milk yield in either environment. Rumen-protected niacin increased plasma and milk niacin concentrations in a linear manner. Heat stress reduced niacin concentration in whole blood (7.86 vs. 6.89μg/mL) but not in milk. Reduced blood niacin concentration was partially corrected by dietary RPN. An interaction existed between dietary RPN and environment; dietary RPN linearly increased water intake in both environments, but the increase was greater during HS conditions. Increasing dietary RPN did not influence skin temperatures. During TN, supplementing 12g/d of RPN increased hair coat (unshaved skin; 30.3 vs. 31.3°C at 1600h) but not shaved skin (32.8 vs. 32.9°C at 1600h) temperature when compared with 0g/d at all time points, whereas the maximum temperature (18°C) of the room was lower than skin temperature. These data suggest that dietary RPN increased water intake during both TN and HS and hair coat temperature during TN; however, core body temperature was unaffected. Thus, encapsulated niacin did not improve thermotolerance of winter-acclimated lactating dairy cows exposed to moderate thermal stress in Arizona.
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Affiliation(s)
- S Rungruang
- School of Animal and Comparative Biomedical Sciences, University of Arizona, Tucson 85721
| | - J L Collier
- School of Animal and Comparative Biomedical Sciences, University of Arizona, Tucson 85721
| | - R P Rhoads
- Department of Animal Sciences, Virginia Tech, Blacksburg 24061
| | - L H Baumgard
- Department of Animal Sciences, Iowa State University, Ames 50011
| | | | - R J Collier
- School of Animal and Comparative Biomedical Sciences, University of Arizona, Tucson 85721.
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111
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Rahman M, Muhammad S, Khan MA, Chen H, Ridder DA, Müller-Fielitz H, Pokorná B, Vollbrandt T, Stölting I, Nadrowitz R, Okun JG, Offermanns S, Schwaninger M. The β-hydroxybutyrate receptor HCA2 activates a neuroprotective subset of macrophages. Nat Commun 2014; 5:3944. [PMID: 24845831 DOI: 10.1038/ncomms4944] [Citation(s) in RCA: 295] [Impact Index Per Article: 29.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2014] [Accepted: 04/22/2014] [Indexed: 12/19/2022] Open
Abstract
The ketone body β-hydroxybutyrate (BHB) is an endogenous factor protecting against stroke and neurodegenerative diseases, but its mode of action is unclear. Here we show in a stroke model that the hydroxy-carboxylic acid receptor 2 (HCA2, GPR109A) is required for the neuroprotective effect of BHB and a ketogenic diet, as this effect is lost in Hca2(-/-) mice. We further demonstrate that nicotinic acid, a clinically used HCA2 agonist, reduces infarct size via a HCA2-mediated mechanism, and that noninflammatory Ly-6C(Lo) monocytes and/or macrophages infiltrating the ischemic brain also express HCA2. Using cell ablation and chimeric mice, we demonstrate that HCA2 on monocytes and/or macrophages is required for the protective effect of nicotinic acid. The activation of HCA2 induces a neuroprotective phenotype of monocytes and/or macrophages that depends on PGD2 production by COX1 and the haematopoietic PGD2 synthase. Our data suggest that HCA2 activation by dietary or pharmacological means instructs Ly-6C(Lo) monocytes and/or macrophages to deliver a neuroprotective signal to the brain.
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Affiliation(s)
- Mahbubur Rahman
- 1] Institute of Experimental and Clinical Pharmacology and Toxicology, University of Lübeck, Ratzeburger Allee 160, 23538 Lübeck, Germany [2]
| | - Sajjad Muhammad
- 1] Institute of Pharmacology, University of Heidelberg, Im Neuenheimer Feld 366, 69120 Heidelberg, Germany [2] [3]
| | - Mahtab A Khan
- 1] Institute of Experimental and Clinical Pharmacology and Toxicology, University of Lübeck, Ratzeburger Allee 160, 23538 Lübeck, Germany [2]
| | - Hui Chen
- Institute of Experimental and Clinical Pharmacology and Toxicology, University of Lübeck, Ratzeburger Allee 160, 23538 Lübeck, Germany
| | - Dirk A Ridder
- Institute of Experimental and Clinical Pharmacology and Toxicology, University of Lübeck, Ratzeburger Allee 160, 23538 Lübeck, Germany
| | - Helge Müller-Fielitz
- Institute of Experimental and Clinical Pharmacology and Toxicology, University of Lübeck, Ratzeburger Allee 160, 23538 Lübeck, Germany
| | - Barbora Pokorná
- Institute of Pharmacology, University of Heidelberg, Im Neuenheimer Feld 366, 69120 Heidelberg, Germany
| | - Tillman Vollbrandt
- Institute for Systemic Inflammation Research, University of Lübeck, Ratzeburger Allee 160, 23538 Lübeck, Germany
| | - Ines Stölting
- Institute of Experimental and Clinical Pharmacology and Toxicology, University of Lübeck, Ratzeburger Allee 160, 23538 Lübeck, Germany
| | - Roger Nadrowitz
- Institute of Radiotherapy and Nuclear Medicine, University of Lübeck, Ratzeburger Allee 160, 23538 Lübeck, Germany
| | - Jürgen G Okun
- Department of Pediatrics, University Hospital, Im Neuenheimer Feld 430, 69120 Heidelberg, Germany
| | - Stefan Offermanns
- 1] Department of Pharmacology, Max-Planck-Institute for Heart and Lung Research, Ludwigstrasse 43, 61231 Bad Nauheim, Germany [2] Medical Faculty, Goethe University, Frankfurt, Germany
| | - Markus Schwaninger
- 1] Institute of Experimental and Clinical Pharmacology and Toxicology, University of Lübeck, Ratzeburger Allee 160, 23538 Lübeck, Germany [2] DZHK (German Research Centre for Cardiovascular Research), partner site Hamburg/Lübeck/Kiel, 23562 Lübeck, Germany
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112
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Niacin in pharmacological doses alters microRNA expression in skeletal muscle of obese Zucker rats. PLoS One 2014; 9:e98313. [PMID: 24847987 PMCID: PMC4029970 DOI: 10.1371/journal.pone.0098313] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2014] [Accepted: 04/30/2014] [Indexed: 01/21/2023] Open
Abstract
Administration of pharmacological niacin doses was recently reported to have pronounced effects on skeletal muscle gene expression and phenotype in obese Zucker rats, with the molecular mechanisms underlying the alteration of gene expression being completely unknown. Since miRNAs have been shown to play a critical role for gene expression through inducing miRNA-mRNA interactions which results in the degradation of specific mRNAs or the repression of protein translation, we herein aimed to investigate the influence of niacin at pharmacological doses on the miRNA expression profile in skeletal muscle of obese Zucker rats fed either a control diet with 30 mg supplemented niacin/kg diet or a high-niacin diet with 780 mg supplemented niacin/kg diet for 4 wk. miRNA microarray analysis revealed that 42 out of a total of 259 miRNAs were differentially expressed (adjusted P-value <0.05), 20 being down-regulated and 22 being up-regulated, between the niacin group and the control group. Using a biostatistics approach, we could demonstrate that the most strongly up-regulated (log2 ratio ≥0.5) and down-regulated (log2 ratio ≤-0.5) miRNAs target approximately 1,800 mRNAs. Gene-term enrichment analysis showed that many of the predicted target mRNAs from the most strongly regulated miRNAs were involved in molecular processes dealing with gene transcription such as DNA binding, transcription regulator activity, transcription factor binding and in important regulatory pathways such as Wnt signaling and MAPK signaling. In conclusion, the present study shows for the first time that pharmacological niacin doses alter the expression of miRNAs in skeletal muscle of obese Zucker rats and that the niacin-regulated miRNAs target a large set of genes and pathways which are involved in gene regulatory activity indicating that at least some of the recently reported effects of niacin on skeletal muscle gene expression and phenotype in obese Zucker rats are mediated through miRNA-mRNA interactions.
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Ma L, Lee BH, Mao R, Cai A, Jia Y, Clifton H, Schaefer S, Xu L, Zheng J. Nicotinic acid activates the capsaicin receptor TRPV1: Potential mechanism for cutaneous flushing. Arterioscler Thromb Vasc Biol 2014; 34:1272-80. [PMID: 24675661 DOI: 10.1161/atvbaha.113.303346] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE Nicotinic acid (also known as niacin or vitamin B3), widely used to treat dyslipidemias, represents an effective and safe means to reduce the risk of mortality from cardiovascular disease. Nonetheless, a substantial fraction of patients discontinue treatment because of a strong side effect of cutaneous vasodilation, commonly termed flushing. In the present study, we tested the hypothesis that nicotinic acid causes flushing partially by activating the capsaicin receptor TRPV1, a polymodal cellular sensor that mediates the flushing response on consumption of spicy food. APPROACH AND RESULTS We observed that the nicotinic acid-induced increase in blood flow was substantially reduced in Trpv1(-/-) knockout mice, indicating involvement of the channel in flushing response. Using exogenously expressed TRPV1, we confirmed that nicotinic acid at submillimolar to millimolar concentrations directly and potently activates TRPV1 from the intracellular side. Binding of nicotinic acid to TRPV1 lowers its activation threshold for heat, causing channel opening at physiological temperatures. The activation of TRPV1 by voltage or ligands (capsaicin and 2-aminoethoxydiphenyl borate) is also potentiated by nicotinic acid. We further demonstrated that nicotinic acid does not compete directly with capsaicin but may activate TRPV1 through the 2-aminoethoxydiphenyl borate activation pathway. Using live-cell fluorescence imaging, we observed that nicotinic acid can quickly enter the cell through a transporter-mediated pathway to activate TRPV1. CONCLUSIONS Direct activation of TRPV1 by nicotinic acid may lead to cutaneous vasodilation that contributes to flushing, suggesting a potential novel pathway to inhibit flushing and to improve compliance.
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Affiliation(s)
- Linlin Ma
- From the Department of Physiology and Membrane Biology (L.M., B.H.L., J.Z.) and Division of Cardiovascular Medicine (H.C., S.S.), University of California School of Medicine, Davis; Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan Province, China (R.M, A.C., Y.J., L.X.); and Institute for Molecular Bioscience, University of Queensland, St Lucia, Queensland, Australia (L.M.)
| | - Bo Hyun Lee
- From the Department of Physiology and Membrane Biology (L.M., B.H.L., J.Z.) and Division of Cardiovascular Medicine (H.C., S.S.), University of California School of Medicine, Davis; Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan Province, China (R.M, A.C., Y.J., L.X.); and Institute for Molecular Bioscience, University of Queensland, St Lucia, Queensland, Australia (L.M.)
| | - Rongrong Mao
- From the Department of Physiology and Membrane Biology (L.M., B.H.L., J.Z.) and Division of Cardiovascular Medicine (H.C., S.S.), University of California School of Medicine, Davis; Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan Province, China (R.M, A.C., Y.J., L.X.); and Institute for Molecular Bioscience, University of Queensland, St Lucia, Queensland, Australia (L.M.)
| | - Anping Cai
- From the Department of Physiology and Membrane Biology (L.M., B.H.L., J.Z.) and Division of Cardiovascular Medicine (H.C., S.S.), University of California School of Medicine, Davis; Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan Province, China (R.M, A.C., Y.J., L.X.); and Institute for Molecular Bioscience, University of Queensland, St Lucia, Queensland, Australia (L.M.)
| | - Yunfang Jia
- From the Department of Physiology and Membrane Biology (L.M., B.H.L., J.Z.) and Division of Cardiovascular Medicine (H.C., S.S.), University of California School of Medicine, Davis; Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan Province, China (R.M, A.C., Y.J., L.X.); and Institute for Molecular Bioscience, University of Queensland, St Lucia, Queensland, Australia (L.M.)
| | - Heather Clifton
- From the Department of Physiology and Membrane Biology (L.M., B.H.L., J.Z.) and Division of Cardiovascular Medicine (H.C., S.S.), University of California School of Medicine, Davis; Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan Province, China (R.M, A.C., Y.J., L.X.); and Institute for Molecular Bioscience, University of Queensland, St Lucia, Queensland, Australia (L.M.)
| | - Saul Schaefer
- From the Department of Physiology and Membrane Biology (L.M., B.H.L., J.Z.) and Division of Cardiovascular Medicine (H.C., S.S.), University of California School of Medicine, Davis; Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan Province, China (R.M, A.C., Y.J., L.X.); and Institute for Molecular Bioscience, University of Queensland, St Lucia, Queensland, Australia (L.M.)
| | - Lin Xu
- From the Department of Physiology and Membrane Biology (L.M., B.H.L., J.Z.) and Division of Cardiovascular Medicine (H.C., S.S.), University of California School of Medicine, Davis; Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan Province, China (R.M, A.C., Y.J., L.X.); and Institute for Molecular Bioscience, University of Queensland, St Lucia, Queensland, Australia (L.M.)
| | - Jie Zheng
- From the Department of Physiology and Membrane Biology (L.M., B.H.L., J.Z.) and Division of Cardiovascular Medicine (H.C., S.S.), University of California School of Medicine, Davis; Kunming Institute of Zoology, Chinese Academy of Sciences, Kunming, Yunnan Province, China (R.M, A.C., Y.J., L.X.); and Institute for Molecular Bioscience, University of Queensland, St Lucia, Queensland, Australia (L.M.).
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Kondaveeti S, Mehta GK, Siddhanta AK. Modification of agarose: 6-aminoagarose mediated syntheses of fluorogenic pyridine carboxylic acid amides. Carbohydr Polym 2014; 106:365-73. [PMID: 24721091 DOI: 10.1016/j.carbpol.2014.02.051] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2013] [Revised: 02/11/2014] [Accepted: 02/15/2014] [Indexed: 11/25/2022]
Abstract
A facile 6-aminoagarose (AA) mediated synthesis of new fluorogenic amides of agarose with nicotinic (AA-NA) and picolinic acids (AA-PA) employing carbodiimide chemistry have been described. 6-Amino agarose (AA) was synthesized in a facile Mitsunobu-inspired microwave mediated method involving the reaction of agarose with phthalimide in presence of diisopropyl azodicarboxylate and triphenylphosphene (DIAD/TPP) followed by hydrazinolysis. All compounds were characterized by GPC, UV spectrophotometry, fluorescence spectroscopy, FT-IR, (1)H and (13)C NMR spectra. The fluorescence emissions (λmax 430 and 412 nm) of 1 × 10(-3)M solutions of AA-NA and AA-PA in water were significantly higher (ca. 82% and ca. 90%) than those of the molar equivalents (0.2mg) of NA and PA present in the 1 × 10(-3)M solutions of the amides, respectively. These fluorogenic pyridine carboxylic acid amides of agarose may find applications as sensors in biomedical and pharmaceutical industries.
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Affiliation(s)
- Stalin Kondaveeti
- Marine Biotechnology and Ecology Discipline, CSIR-Central Salt & Marine Chemicals Research Institute, G. B. Marg, Bhavnagar 364002, Gujarat, India
| | - Gaurav K Mehta
- Marine Biotechnology and Ecology Discipline, CSIR-Central Salt & Marine Chemicals Research Institute, G. B. Marg, Bhavnagar 364002, Gujarat, India
| | - A K Siddhanta
- Marine Biotechnology and Ecology Discipline, CSIR-Central Salt & Marine Chemicals Research Institute, G. B. Marg, Bhavnagar 364002, Gujarat, India; Academy of Scientific & Innovative Research, Anusandhan Bhavan, 2 Rafi Marg, New Delhi 110001, India.
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115
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Activation of Gpr109a, receptor for niacin and the commensal metabolite butyrate, suppresses colonic inflammation and carcinogenesis. Immunity 2014; 40:128-39. [PMID: 24412617 DOI: 10.1016/j.immuni.2013.12.007] [Citation(s) in RCA: 1517] [Impact Index Per Article: 151.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2012] [Accepted: 10/28/2013] [Indexed: 02/07/2023]
Abstract
Commensal gut microflora and dietary fiber protect against colonic inflammation and colon cancer through unknown targets. Butyrate, a bacterial product from fermentation of dietary fiber in the colon, has been implicated in this process. GPR109A (encoded by Niacr1) is a receptor for butyrate in the colon. GPR109A is also a receptor for niacin, which is also produced by gut microbiota and suppresses intestinal inflammation. Here we showed that Gpr109a signaling promoted anti-inflammatory properties in colonic macrophages and dendritic cells and enabled them to induce differentiation of Treg cells and IL-10-producing T cells. Moreover, Gpr109a was essential for butyrate-mediated induction of IL-18 in colonic epithelium. Consequently, Niacr1(-/-) mice were susceptible to development of colonic inflammation and colon cancer. Niacin, a pharmacological Gpr109a agonist, suppressed colitis and colon cancer in a Gpr109a-dependent manner. Thus, Gpr10a has an essential role in mediating the beneficial effects of gut microbiota and dietary fiber in colon.
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116
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Boden WE, Sidhu MS, Toth PP. The Therapeutic Role of Niacin in Dyslipidemia Management. J Cardiovasc Pharmacol Ther 2013; 19:141-58. [DOI: 10.1177/1074248413514481] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
There is abundant epidemiologic evidence to support the independent, inverse relationship between low levels of high-density lipoprotein cholesterol (HDL-C) and incident cardiovascular (CV) risk, the clinical importance of which is underscored by the high prevalence of low HDL-C in populations with coronary heart disease (CHD), with or without elevated levels of low-density lipoprotein cholesterol (LDL-C). The National Cholesterol Education Program recommended that optimal treatment for high-risk patients includes both lowering LDL-C and non-HDL-C to risk stratified levels and raising HDL-C when it is <40 mg/dL, although no target level for the latter lipoprotein was suggested. Niacin is the most powerful agent currently available for raising low levels of HDL-C. It also induces significant reductions in triglycerides, lipoprotein(a), and LDL-C levels while also favorably altering LDL particle size and number. In the Coronary Drug Project, niacin treatment was associated with significant reductions in CV events and long-term mortality, similar to the reductions seen in the statin monotherapy trials. In combination trials, niacin plus a statin or bile acid sequestrant produces additive reductions in CHD morbidity and mortality and promotes regression of coronary atherosclerosis. Recently, 2 clinical outcome trials (Atherothrombosis Intervention in Metabolic Syndrome With Low HDL/High Triglycerides and Impact on Global Health Outcomes [AIM-HIGH] and Second Heart Protection Study [HPS-2 THRIVE]) failed to show a reduction in CV events in patients treated to optimally low levels of LDL-C. Despite favorable effects on HDL-C and triglycerides, these studies did not demonstrate incremental clinical benefit with niacin when added to simvastatin, although notable limitations were identified in each of these trials. Thus, there is insufficient evidence from clinical trials to recommend HDL-targeted therapy for additional event reduction at the present time. However, niacin should continue to be used as an adjuvant therapy for reducing atherogenic lipoprotein burden in patients who have not reached their risk stratified LDL-C and non-HDL-C targets.
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Affiliation(s)
- William E. Boden
- Department of Medicine, Albany Stratton VA Medical Center and Albany Medical Center, Albany Medical College, Albany, NY, USA
| | - Mandeep S. Sidhu
- Department of Medicine, Albany Stratton VA Medical Center and Albany Medical Center, Albany Medical College, Albany, NY, USA
| | - Peter P. Toth
- Department of Family, Community Medicine, University of Illinois School of Medicine, and CGH Medical Center, Sterling, IL, USA
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Scholz K, Kynast AM, Couturier A, Mooren FC, Krüger K, Most E, Eder K, Ringseis R. Supplementing healthy rats with a high-niacin dose has no effect on muscle fiber distribution and muscle metabolic phenotype. Eur J Nutr 2013; 53:1229-36. [PMID: 24271591 DOI: 10.1007/s00394-013-0624-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2013] [Accepted: 11/12/2013] [Indexed: 12/20/2022]
Abstract
PURPOSE It was recently shown that niacin prevents the obesity-induced type I to type II fiber switching in skeletal muscle of obese rats and favors the development of a more oxidative metabolic phenotype and thereby increases whole body utilization of fatty acids. Whether niacin also causes type II to type I fiber switching in skeletal muscle of healthy rats has not been investigated yet. Thus, the present study aimed to investigate whether niacin supplementation influences fiber distribution and metabolic phenotype of different skeletal muscles with a distinct type I-to-type II fiber ratio in healthy rats. METHODS Twenty-four male, 10-week-old Sprague-Dawley rats were randomly assigned into two groups of 12 rats each and fed either a control diet with 30 mg supplemented niacin/kg diet (control group) or a high-niacin diet with 780 mg supplemented niacin/kg diet (high-niacin group). RESULTS After 27 days of treatment, the percentage number of type I fibers in rectus femoris, gastrocnemius, and tibialis anterior muscles was 5-10% greater in the niacin group than in the control group, but did not differ between groups in soleus and vastus intermedius muscles. Transcript levels of genes encoding transcription factors regulating fiber switching, fiber-specific myosin heavy chain isoforms, and proteins involved in fatty acid utilization, oxidative phosphorylation, and angiogenesis did not differ between groups. CONCLUSIONS The results show that niacin has only negligible effects on fiber distribution and its regulation as well as the metabolic phenotype of skeletal muscle in healthy rats.
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Affiliation(s)
- Kristen Scholz
- Institute of Animal Nutrition and Nutrition Physiology, Justus-Liebig-University Giessen, Heinrich-Buff-Ring 26-32, 35390, Giessen, Germany
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118
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Khan M, Couturier A, Kubens JF, Most E, Mooren FC, Krüger K, Ringseis R, Eder K. Niacin supplementation induces type II to type I muscle fiber transition in skeletal muscle of sheep. Acta Vet Scand 2013; 55:85. [PMID: 24267720 PMCID: PMC4176759 DOI: 10.1186/1751-0147-55-85] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2013] [Accepted: 11/12/2013] [Indexed: 11/24/2022] Open
Abstract
Background It was recently shown that niacin supplementation counteracts the obesity-induced muscle fiber transition from oxidative type I to glycolytic type II and increases the number of type I fibers in skeletal muscle of obese Zucker rats. These effects were likely mediated by the induction of key regulators of fiber transition, PPARδ (encoded by PPARD), PGC-1α (encoded by PPARGC1A) and PGC-1β (encoded by PPARGC1B), leading to type II to type I fiber transition and upregulation of genes involved in oxidative metabolism. The aim of the present study was to investigate whether niacin administration also influences fiber distribution and the metabolic phenotype of different muscles [M. longissimus dorsi (LD), M. semimembranosus (SM), M. semitendinosus (ST)] in sheep as a model for ruminants. For this purpose, 16 male, 11 wk old Rhoen sheep were randomly allocated to two groups of 8 sheep each administered either no (control group) or 1 g niacin per day (niacin group) for 4 wk. Results After 4 wk, the percentage number of type I fibers in LD, SM and ST muscles was greater in the niacin group, whereas the percentage number of type II fibers was less in niacin group than in the control group (P < 0.05). The mRNA levels of PPARGC1A, PPARGC1B, and PPARD and the relative mRNA levels of genes involved in mitochondrial fatty acid uptake (CPT1B, SLC25A20), tricarboxylic acid cycle (SDHA), mitochondrial respiratory chain (COX5A, COX6A1), and angiogenesis (VEGFA) in LD, SM and ST muscles were greater (P < 0.05) or tended to be greater (P < 0.15) in the niacin group than in the control group. Conclusions The study shows that niacin supplementation induces muscle fiber transition from type II to type I, and thereby an oxidative metabolic phenotype of skeletal muscle in sheep as a model for ruminants. The enhanced capacity of skeletal muscle to utilize fatty acids in ruminants might be particularly useful during metabolic states in which fatty acids are excessively mobilized from adipose tissue, such as during the early lactating period in high producing cows.
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119
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Jiang RR, Zhao GP, Zhao JP, Chen JL, Zheng MQ, Liu RR, Wen J. Influence of dietary nicotinic acid supplementation on lipid metabolism and related gene expression in two distinct broiler breeds of female chickens. J Anim Physiol Anim Nutr (Berl) 2013; 98:822-9. [DOI: 10.1111/jpn.12138] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- R. R. Jiang
- State Key Laboratory of Animal Nutrition; Institute of Animal Science Chinese Academy of Agricultural Sciences; Beijing China
- College of Livestock Husbandry and Veterinary Engineering Henan Agricultural University; Zhengzhou China
| | - G. P. Zhao
- State Key Laboratory of Animal Nutrition; Institute of Animal Science Chinese Academy of Agricultural Sciences; Beijing China
| | - J. P. Zhao
- State Key Laboratory of Animal Nutrition; Institute of Animal Science Chinese Academy of Agricultural Sciences; Beijing China
| | - J. L. Chen
- State Key Laboratory of Animal Nutrition; Institute of Animal Science Chinese Academy of Agricultural Sciences; Beijing China
| | - M. Q. Zheng
- State Key Laboratory of Animal Nutrition; Institute of Animal Science Chinese Academy of Agricultural Sciences; Beijing China
| | - R. R. Liu
- State Key Laboratory of Animal Nutrition; Institute of Animal Science Chinese Academy of Agricultural Sciences; Beijing China
| | - J. Wen
- State Key Laboratory of Animal Nutrition; Institute of Animal Science Chinese Academy of Agricultural Sciences; Beijing China
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120
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Offermanns S. Free fatty acid (FFA) and hydroxy carboxylic acid (HCA) receptors. Annu Rev Pharmacol Toxicol 2013; 54:407-34. [PMID: 24160702 DOI: 10.1146/annurev-pharmtox-011613-135945] [Citation(s) in RCA: 118] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Saturated and unsaturated free fatty acids (FFAs), as well as hydroxy carboxylic acids (HCAs) such as lactate and ketone bodies, are carriers of metabolic energy, precursors of biological mediators, and components of biological structures. However, they are also able to exert cellular effects through G protein-coupled receptors named FFA1-FFA4 and HCA1-HCA3. Work during the past decade has shown that these receptors are widely expressed in the human body and regulate the metabolic, endocrine, immune and other systems to maintain homeostasis under changing dietary conditions. The development of genetic mouse models and the generation of synthetic ligands of individual FFA and HCA receptors have been instrumental in identifying cellular and biological functions of these receptors. These studies have produced strong evidence that several FFA and HCA receptors can be targets for the prevention and treatment of various diseases, including type 2 diabetes mellitus, obesity, and inflammation.
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Affiliation(s)
- Stefan Offermanns
- Department of Pharmacology, Max-Planck-Institute for Heart and Lung Research, 61231 Bad Nauheim, Germany and Medical Faculty, Goethe University Frankfurt, 60590 Frankfurt am Main, Germany;
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121
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Yang YL, Hu M, Chang M, Tomlinson B. A high incidence of exanthematous eruption associated with niacin/laropiprant combination in Hong Kong Chinese patients. J Clin Pharm Ther 2013; 38:528-32. [DOI: 10.1111/jcpt.12096] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2013] [Accepted: 08/13/2013] [Indexed: 11/30/2022]
Affiliation(s)
- Y.-L. Yang
- Department of Medicine and Therapeutics; Prince of Wales Hospital; The Chinese University of Hong Kong; Shatin Hong Kong
| | - M. Hu
- Department of Medicine and Therapeutics; Prince of Wales Hospital; The Chinese University of Hong Kong; Shatin Hong Kong
| | - M. Chang
- Department of Medicine and Therapeutics; Prince of Wales Hospital; The Chinese University of Hong Kong; Shatin Hong Kong
| | - B. Tomlinson
- Department of Medicine and Therapeutics; Prince of Wales Hospital; The Chinese University of Hong Kong; Shatin Hong Kong
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122
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Khan M, Ringseis R, Mooren FC, Krüger K, Most E, Eder K. Niacin supplementation increases the number of oxidative type I fibers in skeletal muscle of growing pigs. BMC Vet Res 2013; 9:177. [PMID: 24010567 PMCID: PMC3846775 DOI: 10.1186/1746-6148-9-177] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2013] [Accepted: 09/02/2013] [Indexed: 11/20/2022] Open
Abstract
Background A recent study showed that niacin supplementation counteracts the obesity-induced muscle fiber switching from oxidative type I to glycolytic type II and increases the number of type I fibers in skeletal muscle of obese Zucker rats. These effects were likely mediated by the induction of key regulators of fiber transition, PGC-1α and PGC-1β, leading to muscle fiber switching and up-regulation of genes involved in mitochondrial fatty acid import and oxidation, citrate cycle, oxidative phosphorylation, mitochondrial biogenesis. The aim of the present study was to investigate whether niacin supplementation causes type II to type I muscle and changes the metabolic phenotype of skeletal muscles in growing pigs. Results 25 male, 11 wk old crossbred pigs (Danzucht x Pietrain) with an average body weight of 32.8 ± 1.3 (mean ± SD) kg were randomly allocated to two groups of 12 (control group) and 13 pigs (niacin group) which were fed either a control diet or a diet supplemented with 750 mg niacin/kg diet. After 3 wk, the percentage number of type I fibers in three different muscles (M. longissismus dorsi, M. quadriceps femoris, M. gastrocnemius) was greater in the niacin group and the percentage number of type II fibers was lower in the niacin group than in the control group (P < 0.05). The mRNA levels of PGC-1β and genes involved in mitochondrial fatty acid catabolism (CACT, FATP1, OCTN2), citrate cycle (SDHA), oxidative phosphorylation (COX4/1, COX6A1), and thermogenesis (UCP3) in M. longissimus dorsi were greater in the niacin group than in the control group (P < 0.05). Conclusions The study demonstrates that niacin supplementation induces type II to type I muscle fiber switching, and thereby an oxidative metabolic phenotype of skeletal muscle in pigs. Given that oxidative muscle types tend to develop dark, firm and dry pork in response to intense physical activity and/or high psychological stress levels preslaughter, a niacin-induced change in the muscle´s fiber type distribution may influence meat quality of pigs.
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Affiliation(s)
- Muckta Khan
- Institute of Animal Nutrition and Nutrition Physiology, Justus-Liebig-University Giessen, Heinrich-Buff-Ring 26-32, Giessen 35390, Germany.
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Serum nicotinamide adenine dinucleotide levels through disease course in multiple sclerosis. Brain Res 2013; 1537:267-72. [PMID: 23973746 DOI: 10.1016/j.brainres.2013.08.025] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2013] [Revised: 08/02/2013] [Accepted: 08/13/2013] [Indexed: 12/22/2022]
Abstract
The levels of the essential pyridine nucleotide, NAD(+) and its reduced form NADH have not been documented in MS patients. We aimed to investigate NAD(+) and NADH levels in serum in patients with different disease stages and forms of MS. NAD(+) and NADH levels were measured in the serum from 209 patients with relapsing remitting MS (RRMS), 136 with secondary progressive MS (SPMS), 51 with primary progressive MS (PPMS), and 99 healthy controls. All patients were in a clinically stable phase. Serum NAD(+) levels declined by at least 50% in patients with MS compared to controls (17.9 ± 3.2 μg/ml; p=0.0012). Within the MS sub-groups NAD(+) levels were higher in RRMS (9.9 ± 2.9 μg/ml; p=0.001) compared to PPMS (6.3 ± 2.1 μg/ml; p=0.003) and SPMS (7.8 ± 2.0 μg/ml; p=0.005). A two-fold increase in NADH levels (p=0.002) and at least three-fold reduction in the NAD(+)/NADH ratio (p=0.009) were observed in MS patients compared to controls. Serum NAD(+) and NADH levels are may be associated with disease progression in MS. Given the importance of NAD(+) in the maintenance of normal cellular function, it is likely that this molecule is of therapeutic relevance in MS.
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Abstract
Niacin (nicotinic acid) has been used for decades as a lipid-lowering drug. The clinical use of niacin to treat dyslipidemic conditions is limited by its side effects. Niacin, along with fibrates, are the only approved drugs which elevate high density lipoprotein cholesterol (HDLc) along with its effects on low density lipoprotein cholesterol (LDLc) and triglycerides. Whether niacin has a beneficial role in lowering cardiovascular risk on the background of well-controlled LDLc has not been established. In fact, it remains unclear whether niacin, either in the setting of well-controlled LDLc or in combination with other lipid-lowering agents, confers any therapeutic benefit and if so, by which mechanism. The results of recent trials reject the hypothesis that simply raising HDLc is cardioprotective. However, in the case of the clinical trials, structural limitations of trial design complicate their interpretation. This is also true of the most recent Heart Protection Study 2-Treatment of HDLc to Reduce the Incidence of Vascular Events (HPS2-THRIVE) trial in which niacin is combined with an antagonist of the D prostanoid (DP) receptor. Human genetic studies have also questioned the relationship between cardiovascular benefit and HDLc. It remains to be determined whether niacin may have clinical utility in particular subgroups, such as statin intolerant patients with hypercholesterolemia or those who cannot achieve a sufficient reduction in LDLc. It also is unclear whether a potentially beneficial effect of niacin is confounded by DP antagonism in HPS2-THRIVE.
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Affiliation(s)
- Wen-Liang Song
- Institute for Translational Medicine and Therapeutics, Departments of Pharmacology and Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104
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125
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Badelin VG, Tyunina EY, Mezhevoi IN, Tarasova GN. Thermodynamic characteristics of the interaction between nicotinic acid and phenylalanine in an aqueous buffer solution at 298 K. RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY A 2013. [DOI: 10.1134/s0036024413070078] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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126
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Abstract
The antiatherogenic drug nicotinic acid (niacin) has antidyslipidemic effects independent of free fatty acid suppression mediated by its receptor HCA₂ (GPR109A) (Lauring et al., this issue).
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Affiliation(s)
- Stefan Offermanns
- Department of Pharmacology, Max Planck Institute for Heart and Lung Research, Ludwigstr. 43, 61231 Bad Nauheim, Germany.
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127
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Sonne SR, Bhalla VK, Barman SA, White RE, Zhu S, Newman TM, Prasad PD, Smith SB, Offermanns S, Ganapathy V. Hyperhomocysteinemia is detrimental to pregnancy in mice and is associated with preterm birth. Biochim Biophys Acta Mol Basis Dis 2013; 1832:1149-58. [PMID: 23579073 DOI: 10.1016/j.bbadis.2013.04.006] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2013] [Revised: 03/28/2013] [Accepted: 04/01/2013] [Indexed: 11/28/2022]
Abstract
Elevated levels of homocysteine produce detrimental effects in humans but its role in preterm birth is not known. Here we used a mouse model of hyperhomocysteinemia to examine the relevance of homocysteine to preterm birth. The mouse carries a heterozygous deletion of cystathionine β-synthase (Cbs(+/-)). Gestational period was monitored in wild type and Cbs(+/-) female mice. Mouse uterine and placental tissues, human primary trophoblast cells, and human myometrial and placental cell lines were used to determine the influence of homocysteine on expression of specific genes in vitro. The activity of BKCa channel in the myometrial cell line was monitored using the patch-clamp technique. We found that hyperhomocysteinemia had detrimental effects on pregnancy and induced preterm birth in mice. Homocysteine increased the expression of oxytocin receptor and Cox-2 as well as PGE2 production in uterus and placenta, and initiated premature uterine contraction. A Cox-2 inhibitor reversed these effects. Gpr109a, a receptor for niacin, induced Cox-2 in uterus. Homocysteine upregulated GPR109A and suppressed BKCa channel activity in human myometrial cells. Deletion of Gpr109a in Cbs(+/-) mice reversed premature birth. We conclude that hyperhomocysteinemia causes preterm birth in mice through upregulation of the Gpr109a/Cox-2/PGE2 axis and that pharmacological blockade of Gpr109a may have potential in prevention of preterm birth.
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Affiliation(s)
- S R Sonne
- Department of Biochemistry and Molecular Biology, Georgia Regents University, Augusta, GA 30912, USA.
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128
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Dou X, Shen C, Wang Z, Li S, Zhang X, Song Z. Protection of nicotinic acid against oxidative stress-induced cell death in hepatocytes contributes to its beneficial effect on alcohol-induced liver injury in mice. J Nutr Biochem 2013; 24:1520-8. [PMID: 23465591 DOI: 10.1016/j.jnutbio.2012.12.012] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2012] [Revised: 12/10/2012] [Accepted: 12/28/2012] [Indexed: 12/14/2022]
Abstract
Oxidative stress plays a pathological role in the development of alcoholic liver disease. In this study, we investigated the effects of nicotinic acid (NA) supplementation on H2O2-induced cell death in hepatocytes and alcohol-induced liver injury in mice. Hepatocytes were exposed to H2O2 (0-0.4 mM) for 16 h after a 2-h pretreatment with NA (0-100 μM). Cell viability, intracellular glutathione and total NAD contents were determined. In animal experiments, male C57BL/6 mice were exposed to Lieber-De Carli liquid diet [+/- ethanol with/without NA supplementation (0.5%, w/v) for 4 weeks]. Nicotinic acid phosphoribosyltransferase (NaPRT) is the first enzyme participated in the NA metabolism, converting NA to nicotinic acid mononucleotide (NaMN). In NaPRT-expressing Hep3B cells, H2O2-induced cell death was attenuated by NA, whereas in NaPRT-lost HepG2 cells, only NaMN conferred protective effect, suggesting that NA metabolism is required for its protective action against H2O2. In Hep3B cells, NA supplementation prevented H2O2-inudced declines in intracellular total NAD and GSH/GSSG ratios. Further mechanistic investigations revealed that conservation of Akt activity contributed to NA's protective effect against H2O2-inudced cell death. In alcohol-fed mice, NA supplementation attenuated liver injury induced by chronic alcohol exposure, which was associated with alleviated hepatic lipid peroxidation and increased liver GSH concentrations. In conclusion, our findings indicate that exogenous NA supplementation may be an ideal choice for the treatment of liver diseases that involve oxidative stress.
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Affiliation(s)
- Xiaobing Dou
- College of Life Science, Zhejiang Chinese Medical University, Hangzhou, Zhejiang 310053, P R China
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129
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Zimbelman R, Collier R, Bilby T. Effects of utilizing rumen protected niacin on core body temperature as well as milk production and composition in lactating dairy cows during heat stress. Anim Feed Sci Technol 2013. [DOI: 10.1016/j.anifeedsci.2013.01.005] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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130
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Ringseis R, Rosenbaum S, Gessner DK, Herges L, Kubens JF, Mooren FC, Krüger K, Eder K. Supplementing obese Zucker rats with niacin induces the transition of glycolytic to oxidative skeletal muscle fibers. J Nutr 2013; 143:125-31. [PMID: 23256146 DOI: 10.3945/jn.112.164038] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
In the present study, we tested the hypothesis that niacin increases the oxidative capacity of muscle by increasing the oxidative type I muscle fiber content. Twenty-four obese Zucker rats were assigned to 2 groups of 12 rats that were fed either a control diet (O group) or a diet supplemented with 750 mg/kg diet niacin (O+N group) for 4 wk. In addition, one group of lean rats (L group) was included in the experiment and fed the control diet for 4 wk. Plasma and liver concentrations of TG were markedly greater in obese groups than in the L group but markedly lower in the O+N group than in the O group (P < 0.05). Rats of the O+N group had a higher percentage of oxidative type I fibers and higher mRNA levels of genes encoding regulators of muscle fiber composition (Ppard, Ppargc1a, Ppargc1b), angiogenic factors (Vegfa, Vegfb), and genes involved in fatty acid utilization (Cpt1b, Slc25a20, Slc22a4, Slc22a5, Slc27a1) and oxidative phosphorylation (Cox4i1, Cox6a2) and a higher activity of the mitochondrial oxidative enzyme succinate dehydrogenase in muscle than rats of the O and L groups (P < 0.05). These niacin-induced changes in muscle metabolic phenotype are indicative of an increased capacity of muscle for oxidative utilization of fatty acids and are likely mediated by the upregulation of Ppard, Ppargc1a, and Ppargc1b, which are key regulators of muscle fiber composition, mitochondrial biogenesis, angiogenesis, and genes involved in fatty acid catabolism and oxidative phosphorylation. The increased utilization of fatty acids by muscle might contribute to the strong TG-lowering effect of niacin treatment.
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Affiliation(s)
- Robert Ringseis
- Institute of Animal Nutrition and Nutrition Physiology, Justus-Liebig-University, Giessen,Germany
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131
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Phan BAP, Muñoz L, Shadzi P, Isquith D, Triller M, Brown BG, Zhao XQ. Effects of niacin on glucose levels, coronary stenosis progression, and clinical events in subjects with normal baseline glucose levels (<100 mg/dl): a combined analysis of the Familial Atherosclerosis Treatment Study (FATS), HDL-Atherosclerosis Treatment Study (HATS), Armed Forces Regression Study (AFREGS), and Carotid Plaque Composition by MRI during lipid-lowering (CPC) study. Am J Cardiol 2013; 111:352-5. [PMID: 23168285 DOI: 10.1016/j.amjcard.2012.09.034] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/18/2012] [Revised: 09/30/2012] [Accepted: 09/30/2012] [Indexed: 12/18/2022]
Abstract
Although the effect of niacin on the glucose levels in subjects with diabetes mellitus has been investigated, niacin's effects on the glucose levels and atherosclerosis in subjects with normal glucose levels have not been well established. We examined the effect of niacin on the glucose levels, coronary stenosis progression using quantitative coronary angiography, and clinical events in 407 subjects who had a baseline glucose level <100 mg/dl and were enrolled in the Familial Atherosclerosis Treatment Study (FATS), HDL-Atherosclerosis Treatment Study (HATS), Armed Forces Regression Study (AFREGS), or Carotid Plaque Composition by MRI during lipid-lowering (CPC) study testing active niacin therapy. Although the fasting glucose levels increased significantly within 3 years in both subjects treated with niacin (from 85.6 ± 9.5 to 95.5 ± 19.7 mg/dl, p <0.001) and without niacin (from 85.2 ± 9.6 to 90 ± 17.9 mg/dl, p = 0.009), those treated with niacin had a significantly larger increase in glucose levels than those not taking niacin (9.88 vs 4.05 mg/dl, p = 0.002). Overall, 29% of subjects developed impaired fasting glucose within 3 years. Incident impaired fasting glucose was significantly more likely to be observed in subjects treated with niacin than in those who were not. However, the frequency of new-onset diabetes mellitus did not differ significantly between the 2 groups (5.6% vs 4.8%, p = 0.5). Niacin-treated subjects compared to untreated subjects had significantly less change in mean coronary stenosis (0.1 ± 0.3% vs 2 ± 12%, p <0.0001) and less major cardiovascular events (8% vs 21%, p = 0.001). In conclusion, the use of niacin for 3 years in subjects with normal baseline glucose levels was associated with an increase in blood glucose levels and the risk of developing impaired fasting glucose, but not diabetes mellitus, and was associated with a significantly reduced incidence of coronary stenosis progression and major cardiovascular events.
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Qureshi AA, Khan DA, Mahjabeen W, Papasian CJ, Qureshi N. Nutritional Supplement-5 with a Combination of Proteasome Inhibitors (Resveratrol, Quercetin, δ-Tocotrienol) Modulate Age-Associated Biomarkers and Cardiovascular Lipid Parameters in Human Subjects. ACTA ACUST UNITED AC 2013; 4. [PMID: 24319627 DOI: 10.4172/2155-9880.1000238] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND Age-associated altered redox imbalances and dysregulated immune function, contribute to the development of a variety of age associated diseases. Inflammatory markers and lipid profiles are useful prognostic indicators of a variety of age-associated and cardiovascular diseases. We have previously studied the impact of several proteasome inhibitors on several markers of inflammation and lipid profiles in vitro, in vivo, in cell lines, animal models, and in human subjects. The current study represents an extension of this work. Our main hypothesis is that a combination of various naturally-occurring proteasome inhibitors, which inhibits nitric oxide (NO), and C-reactive protein (CRP) mediated inflammation, will have better efficacy in the prevention and treatment of age-associated disorders including cardiovascular disease. METHODS Two double blind, randomized, placebo-controlled cross-over trials were conducted to determine the impact of a mixture of NS-5 (resveratrol, pterostilbene, quercetin, δ-tocotrienol, nicotinic acid) on serum NO, CRP, γ-glutamyl-transferase (γ-GT) activity, total antioxidant status (TAS), total cholesterol, LDL-cholesterol, HDL-cholesterol and triglycerides levels. Healthy seniors (Group-1; n = 32) free-living (A, B; 16/group), and hypercholesterolemic (Group-2; n = 64) subjects on AHA-Step-1-diet were divided into two groups (C, D; 32/group). Baseline levels were established for parameters as mentioned above. Groups A, C were administered 4-capsules/d of NS-5 and groups B, D, placebo (starch) for 6-weeks. Groups were crossed-over, followed by a 2-week wash-out period. Groups A, C were given 4-capsules/d of placebo and groups B, D, 4-capsules/d of NS-5 for 6-weeks. Groups C, D were continued on AHA-Step-1-diet. RESULTS All the subjects completed each phase in both studies without any complaints. There were significant ( P < 0.01 - 0.05) decreases in the serum levels of NO (30%, 26%), CRP (29%, 21%), γ-GT activity (14%, 17%), and blood pressure (systolic/diastolic, 3/6%, 3/3%) of Groups A and B, respectively, of free-living healthy seniors without affecting the total, HDL-, LDL-cholesterol or triglycerides compared to their respective baseline values. However, serum levels of NO (36%, 43%), CRP (31%, 48%), γ-GT (17%, 20%), total cholesterol (19%, 15%), LDL-cholesterol (28%, 20%), triglycerides (11%, 18%) of Groups C and D were significantly ( P < 0.01-0.05) decreased with NS-5 treatment of hypercholesterolemic subjects compared to baseline values, without affecting the serum HDL-cholesterol levels. The serum levels of total antioxidant status (TAS) were increased (10%, 14%; P < 0.05) in Groups A and B, increased (19%, 24%; P < 0.02), and blood pressure (systolic/diastolic, 5/6%, 3/5%) in Groups C and D with NS-5 treatment, compared to respective baseline values. CONCLUSIONS The consumption of NS-5 mixture decreased significantly serum NO, CRP and γ-GT levels, improved TAS and lipid profiles at risk cardiovascular and hold promise for delaying onset of age-associated diseases.
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Affiliation(s)
- Asaf A Qureshi
- Department of Basic Medical Science, University of Missouri-Kansas City, 2411 Holmes Street, Kansas City, MO 64108, USA
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133
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Abstract
BACKGROUND The use of niacin in the treatment of dyslipidemias is limited by the common side effect of cutaneous vasodilation, commonly termed flushing. Flushing is thought to be due to release of the vasodilatory prostanoids prostaglandin D2 (PGD2) and prostaglandin E2 from arachidonic acid metabolism through the cyclooxygenase pathway. Arachidonic acid is also metabolized by the cytochrome P450 system, which is regulated, in part, by the enzyme soluble epoxide hydrolase (sEH). METHODS These experiments used an established murine model in which ear tissue perfusion was measured by laser Doppler to test the hypothesis that inhibition of sEH would limit niacin-induced flushing. RESULTS Niacin-induced flushing was reduced from 506 ± 126% to 213 ± 39% in sEH knockout animals. Pharmacologic treatment with 3 structurally distinct sEH inhibitors similarly reduced flushing in a dose-dependent manner, with maximal reduction to 143% ± 15% of baseline flow using a concentration of 1 mg/kg TPAU (1-trifluoromethoxyphenyl-3-(1-acetylpiperidin-4-yl) urea). Systemically administered PGD2 caused ear vasodilation, which was not changed by either pharmacologic sEH inhibition or sEH gene deletion. CONCLUSIONS Inhibition of sEH markedly reduces niacin-induced flushing in this model without an apparent effect on the response to PGD2. sEH inhibition may be a new therapeutic approach to limit flushing in humans.
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Tonack S, Tang C, Offermanns S. Endogenous metabolites as ligands for G protein-coupled receptors modulating risk factors for metabolic and cardiovascular disease. Am J Physiol Heart Circ Physiol 2012; 304:H501-13. [PMID: 23241321 DOI: 10.1152/ajpheart.00641.2012] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
During the last decade, several G protein-coupled receptors activated by endogenous metabolites have been described. These receptors respond to fatty acids, mono- and disaccharides, amino acids, or various intermediates and products of metabolism, including ketone bodies, lactate, succinate, or bile acids. Receptors of endogenous metabolites are expressed in taste cells, the gastrointestinal tract, adipose tissue, endocrine glands, immune cells, or the kidney and are therefore in a position to sense food intake in the gastrointestinal tract or to link metabolite levels to the appropriate responses of metabolic organs. Some of the receptors appear to provide a link between metabolic and neuronal or immune functions. Given that many of these metabolic processes are dysregulated under pathological conditions, including diabetes, dyslipidemia, and obesity, receptors of endogenous metabolites have also been recognized as potential drug targets to prevent and/or treat metabolic and cardiovascular diseases. This review describes G protein-coupled receptors activated by endogenous metabolites and summarizes their physiological, pathophysiological, and potential pharmacological roles.
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Affiliation(s)
- Sarah Tonack
- Department of Pharmacology, Max Planck Institute for Heart and Lung Research, Bad Nauheim, Germany
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135
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Abstract
Excess of adipose tissue is accompanied by an increase in the risk of developing insulin resistance, type 2 diabetes (T2D) and other complications. Nevertheless, total or partial absence of fat or its accumulation in other tissues (lipotoxicity) is also associated to these complications. White adipose tissue (WAT) was traditionally considered a metabolically active storage tissue for lipids while brown adipose tissue (BAT) was considered as a thermogenic adipose tissue with higher oxidative capacity. Nowadays, WAT is also considered an endocrine organ that contributes to energy homeostasis. Experimental evidence tends to link the malfunction of adipose mitochondria with the development of obesity and T2D. This review discusses the importance of mitochondrial function in adipocyte biology and the increased evidences of mitochondria dysfunction in these epidemics. New strategies targeting adipocyte mitochondria from WAT and BAT are also discussed as therapies against obesity and its complications in the near future.
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Affiliation(s)
- Gema Medina-Gómez
- Dpto. de Bioquímica, Fisiología y Genética Molecular, Universidad Rey Juan Carlos, Facultad de Ciencias de la Salud, Avda. de Atenas s/n, 28922 Alcorcón, Madrid, Spain.
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Mielenz M, Kuhla B, Hammon HM. Abundance of adiponectin system and G-protein coupled receptor GPR109A mRNA in adipose tissue and liver of F2 offspring cows of Charolais × German Holstein crosses that differ in body fat accumulation. J Dairy Sci 2012; 96:278-89. [PMID: 23141824 DOI: 10.3168/jds.2012-5816] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2012] [Accepted: 09/18/2012] [Indexed: 12/13/2022]
Abstract
In addition to its role in energy storage, adipose tissue (AT) is an important endocrine organ and it secretes adipokines. The adipokine adiponectin improves insulin sensitivity by activation of its receptors AdipoR1 and AdipoR2. Lipolysis in AT is downregulated by the G-protein coupled receptor (GPR109A), which binds the endogenous ligand β-hydroxybutyrate (BHBA). Insulin sensitivity is reduced during the transition from late pregnancy to early lactation in dairy cattle and BHBA is increased postpartum, implying the involvement of the adiponectin system and GPR109A in this process. The aim of the current investigation was to study the effect of the genetic background of cows on the mRNA abundance of the adiponectin system, as well as GPR109A, in an F(2) population of 2 Charolais × German Holstein families. These families were deduced from full- and half-sibs sharing identical but reciprocal paternal and maternal Charolais grandfathers. The animals of the 2 families showed significant differences in fat accretion and milk secretion and were designated fat-type (high fat accretion but low milk production) and lean-type (low fat accretion but high milk production). The mRNA of the adiponectin system and GPR109A were quantified by real-time PCR in different fat depots (subcutaneous from back, mesenteric, kidney) and liver. The mRNA data were correlated with AT masses (intermuscular topside border fat, kidney, mesenteric, omental, total inner fat mass, total subcutaneous fat mass, and total fat mass) and blood parameters (glucose, nonesterified fatty acids, BHBA, urea, insulin, and glucagon). The abundance of adiponectin system mRNA was higher in discrete AT depots of fat-type cows [adiponectin mRNA in mesenteric fat (trend), AdipoR1 in kidney and mesenteric AT, and AdipoR2 in subcutaneous fat (trend)] than in lean-type cows. More GPR109A mRNA was found in kidney fat of the lean-type family than in that of the fat-type family. In liver, the abundance of AdipoR2 and GPR109A (trend) mRNA was higher in lean-type than in fat-type cows. Correlation analyses disclosed clear differences between the groups. In total, the results revealed obvious disparities for the mRNA targets between the 2 families with common but reciprocal paternal and maternal genetic backgrounds. Visceral AT mass of both families showed most correlations with the mRNA abundance of the target genes in different AT depots. The effect of adiponectin secretion, especially by visceral AT depots, on liver metabolism should be clarified in further studies.
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Affiliation(s)
- M Mielenz
- Institute of Animal Science, Physiology and Hygiene Group, University of Bonn, 53115 Bonn, Germany.
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137
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Miller MM, Liu Y, Jiang J, Johnson JA, Kamau M, Nirschl DS, Wang Y, Harikrishnan L, Taylor DS, Chen AYA, Yin X, Seethala R, Peterson TL, Zvyaga T, Zhang J, Huang CS, Wexler RR, Poss MA, Michael Lawrence R, Adam LP, Salvati ME. Identification of a potent and metabolically stable series of fluorinated diphenylpyridylethanamine-based cholesteryl ester transfer protein inhibitors. Bioorg Med Chem Lett 2012; 22:6503-8. [DOI: 10.1016/j.bmcl.2012.08.011] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2012] [Revised: 07/25/2012] [Accepted: 08/01/2012] [Indexed: 10/28/2022]
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138
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Hanson J, Gille A, Offermanns S. Role of HCA2 (GPR109A) in nicotinic acid and fumaric acid ester-induced effects on the skin. Pharmacol Ther 2012; 136:1-7. [DOI: 10.1016/j.pharmthera.2012.06.003] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2012] [Accepted: 06/08/2012] [Indexed: 11/16/2022]
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139
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Abstract
Niacin, or water-soluble vitamin B(3), when given at pharmacologic doses, is a powerful lipid-altering agent. This drug, which lowers the levels of atherogenic, apolipoprotein-B-containing lipoproteins, is one of few medications that can raise the levels of atheroprotective HDL cholesterol. Niacin also has beneficial effects on other cardiovascular risk factors, including lipoprotein(a), C-reactive protein, platelet-activating factor acetylhydrolase, plasminogen activator inhibitor 1 and fibrinogen. Many clinical trials have confirmed the lipid effects of niacin treatment; however, its effects on cardiovascular outcomes have been called into question owing to the AIM-HIGH trial, which showed no benefit of niacin therapy on cardiovascular endpoints. Furthermore, use of niacin has historically been limited by tolerability issues. In addition to flushing, worsened hyperglycaemia among patients with diabetes mellitus has also been a concern with niacin therapy. This article reviews the utility of niacin including its mechanism of action, clinical trial data regarding cardiovascular outcomes, adverse effect profile and strategies to address these effects and improve compliance.
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Affiliation(s)
- Julia C Creider
- Robarts Research Institute and Schulich School of Medicine and Dentistry, University of the Western Ontario, 100 Perth Drive, N6A 5K8 London, Ontario, Canada
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140
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Lauring B, Taggart AKP, Tata JR, Dunbar R, Caro L, Cheng K, Chin J, Colletti SL, Cote J, Khalilieh S, Liu J, Luo WL, MacLean AA, Peterson LB, Polis AB, Sirah W, Wu TJ, Liu X, Jin L, Wu K, Boatman PD, Semple G, Behan DP, Connolly DT, Lai E, Wagner JA, Wright SD, Cuffie C, Mitchel YB, Rader DJ, Paolini JF, Waters MG, Plump A. Niacin Lipid Efficacy Is Independent of Both the Niacin Receptor GPR109A and Free Fatty Acid Suppression. Sci Transl Med 2012; 4:148ra115. [DOI: 10.1126/scitranslmed.3003877] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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141
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G protein-coupled receptors for energy metabolites as new therapeutic targets. Nat Rev Drug Discov 2012; 11:603-19. [PMID: 22790105 DOI: 10.1038/nrd3777] [Citation(s) in RCA: 200] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Several G protein-coupled receptors (GPCRs) that are activated by intermediates of energy metabolism - such as fatty acids, saccharides, lactate and ketone bodies - have recently been discovered. These receptors are able to sense metabolic activity or levels of energy substrates and use this information to control the secretion of metabolic hormones or to regulate the metabolic activity of particular cells. Moreover, most of these receptors appear to be involved in the pathophysiology of metabolic diseases such as diabetes, dyslipidaemia and obesity. This Review summarizes the functions of these metabolite-sensing GPCRs in physiology and disease, and discusses the emerging pharmacological agents that are being developed to target these GPCRs for the treatment of metabolic disorders.
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142
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Massudi H, Grant R, Guillemin GJ, Braidy N. NAD+ metabolism and oxidative stress: the golden nucleotide on a crown of thorns. Redox Rep 2012; 17:28-46. [PMID: 22340513 DOI: 10.1179/1351000212y.0000000001] [Citation(s) in RCA: 99] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
In the twentieth century, NAD+ research generated multiple discoveries. Identification of the important role of NAD+ as a cofactor in cellular respiration and energy production was followed by discoveries of numerous NAD+ biosynthesis pathways. In recent years, NAD+ has been shown to play a unique role in DNA repair and protein deacetylation. As discussed in this review, there are close interactions between oxidative stress and immune activation, energy metabolism, and cell viability in neurodegenerative disorders and ageing. Profound interactions with regard to oxidative stress and NAD+ have been highlighted in the present work. This review emphasizes the pivotal role of NAD+ in the regulation of DNA repair, stress resistance, and cell death, suggesting that NAD+ synthesis through the kynurenine pathway and/or salvage pathway is an attractive target for therapeutic intervention in age-associated degenerative disorders. NAD+ precursors have been shown to slow down ageing and extend lifespan in yeasts, and protect severed axons from degeneration in animal models neurodegenerative diseases.
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Affiliation(s)
- Hassina Massudi
- Department of Pharmacology, School of Medical Sciences, University of New South Wales, Faculty of Medicine, and Australasian Research Institute, Sydney Adventist Hospital, Sydney, Australia
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143
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Villines TC, Kim AS, Gore RS, Taylor AJ. Niacin: the evidence, clinical use, and future directions. Curr Atheroscler Rep 2012; 14:49-59. [PMID: 22037771 DOI: 10.1007/s11883-011-0212-1] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The use of FDA-approved niacin (nicotinic acid or vitamin B3) formulations at therapeutic doses, alone or in combination with statins or other lipid therapies, is safe, improves multiple lipid parameters, and reduces atherosclerosis progression. Niacin is unique as the most potent available lipid therapy to increase high-density lipoprotein (HDL) cholesterol and it significantly reduces lipoprotein(a). Through its action on the GPR109A receptor, niacin may also exert beneficial pleiotropic effects independent of changes in lipid levels, such as improving endothelial function and attenuating vascular inflammation. Studies evaluating the impact of niacin in statin-naïve patients on cardiovascular outcomes, or alone and in combination with statins or other lipid therapies on atherosclerosis progression, have been universally favorable. However, the widespread use of niacin to treat residual lipid abnormalities such as low HDL cholesterol, when used in combination with statins among patients achieving very low (<75 mg/dL) low-density lipoprotein cholesterol levels, is currently not supported by clinical outcome trials.
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Affiliation(s)
- Todd C Villines
- Cardiology Service, Department of Medicine, Walter Reed National Military Medical Center, 8901 Rockville Pike, Bethesda, MD 20889, USA.
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144
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Besler C, Lüscher TF, Landmesser U. Molecular mechanisms of vascular effects of High-density lipoprotein: alterations in cardiovascular disease. EMBO Mol Med 2012; 4:251-68. [PMID: 22431312 PMCID: PMC3376856 DOI: 10.1002/emmm.201200224] [Citation(s) in RCA: 152] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2011] [Revised: 01/28/2012] [Accepted: 02/03/2012] [Indexed: 12/12/2022] Open
Abstract
Low high-density lipoprotein (HDL)-cholesterol levels are associated with an increased risk of coronary artery disease (CAD) and myocardial infarction, which has triggered the hypothesis that HDL, in contrast to low-density lipoprotein (LDL), acts as an anti-atherogenic lipoprotein. Moreover, experimental studies have identified potential anti-atherogenic properties of HDL, including promotion of macrophage cholesterol efflux and direct endothelial-protective effects of HDL, such as stimulation of endothelial nitric oxide production and repair, anti-apoptotic, anti-inflammatory and anti-thrombotic properties. Studies in gene-targeted mice, however, have also indicated that increasing HDL-cholesterol plasma levels can either limit (e.g. apolipoprotein A-I) or accelerate (e.g. Scavenger receptor class B type I) atherosclerosis. Moreover, vascular effects of HDL have been observed to be heterogenous and are altered in patients with CAD or diabetes, a condition that has been termed 'HDL dysfunction'. These alterations in biological functions of HDL may need to be taken into account for HDL-targeted therapies and considering raising of HDL-cholesterol levels alone is likely not sufficient in this respect. It will therefore be important to further determine, which biological functions of HDL are critical for its anti-atherosclerotic properties, as well as how these can be measured and targeted.
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Affiliation(s)
- Christian Besler
- Department of Cardiology, Cardiovascular Center, University Hospital Zurich, Zurich, Switzerland
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145
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Titgemeyer EC, Mamedova LK, Spivey KS, Farney JK, Bradford BJ. An unusual distribution of the niacin receptor in cattle. J Dairy Sci 2012; 94:4962-7. [PMID: 21943747 DOI: 10.3168/jds.2011-4193] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2011] [Accepted: 06/01/2011] [Indexed: 11/19/2022]
Abstract
Responses to pharmacological doses of niacin, an agonist for GPR109A (niacin receptor), were different in cattle than in humans and rodents. Thus, the tissue distribution of GPR109A was investigated in cattle. Samples of tail head fat, back fat, perirenal fat, longissimus muscle, and liver were analyzed for abundance of GPR109A mRNA by quantitative real-time reverse transcription-PCR and for abundance of GPR109A protein by Western blotting. Niacin receptor transcript and protein were detected in all tissues analyzed. The mRNA for GPR109A was more abundant in liver than in the other tissues sampled (GPR109A:RPS9 mRNA abundance = 0.56 in liver compared with 0.06 in longissimus muscle, 0.15 in kidney fat, 0.11 in back fat, 0.23 in tail head fat; standard error of the mean = 0.028). Additionally, mRNA for GPR109A was found (GPR109A:RPS9 mRNA abundance ≥ 0.004) in each of the 5 regions of bovine brain that were analyzed: cerebral cortex, cerebellum, thalamus, hypothalamus, and brain stem. Evaluation of liver tissue by immunofluorescence suggested that GPR109A was expressed in parenchymal cells and not localized exclusively to immune-system cells. Finally, analysis of the putative bovine GPR109A sequence verified that AA residues required for binding niacin in human GPR109A are conserved, suggesting that the bovine sequence identified encodes a functional niacin receptor. The identification of GPR109A in bovine liver, muscle, and brain is a novel finding.
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Affiliation(s)
- E C Titgemeyer
- Department of Animal Sciences and Industry, Kansas State University, Manhattan 66506, USA.
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146
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Drummond PD, Lazaroo D. The effect of facial blood flow on ratings of blushing and negative affect during an embarrassing task: preliminary findings. J Anxiety Disord 2012; 26:305-10. [PMID: 22257642 DOI: 10.1016/j.janxdis.2011.12.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2011] [Revised: 12/20/2011] [Accepted: 12/25/2011] [Indexed: 10/14/2022]
Abstract
Expecting to blush is a common source of social anxiety, and is associated with heightened perceptions of blushing and embarrassment. To assess whether sensory cues associated with heightened facial blood flow are an additional source of anxiety, the vasodilator niacin (100mg) or placebo was administered double-blind to 33 participants, and facial blood flow was investigated when they sang a children's song. Vasodilatation during singing was greater in the niacin than placebo condition, and niacin-evoked flushing and increases in pulse rate were greater in participants with high than low fear of negative evaluation. Nevertheless, ratings of embarrassment, anxiety, blushing and facial heat were similar in both drug conditions. This dissociation implies that cognitive appraisals or negative affect overrode more subtle physiological cues of blushing during embarrassment. Clarifying how judgments about blushing are made could be crucial for correcting faulty assumptions about blushing in people who are frightened of this response.
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Affiliation(s)
- Peter D Drummond
- School of Psychology, Murdoch University, Perth, Western Australia, Australia
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147
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Hu M, Chu WCW, Yamashita S, Yeung DKW, Shi L, Wang D, Masuda D, Yang Y, Tomlinson B. Liver fat reduction with niacin is influenced by DGAT-2 polymorphisms in hypertriglyceridemic patients. J Lipid Res 2012; 53:802-9. [PMID: 22315393 DOI: 10.1194/jlr.p023614] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Niacin reduces plasma triglycerides, but it may increase free fatty acids and insulin resistance during long-term treatment. We examined the effect of extended-release niacin on liver fat content in Chinese patients with dyslipidemia and whether the common diacylglycerol acyltransferase-2 (DGAT2) polymorphisms influenced this effect. The 39 patients (baseline liver fat content: 12.8 ± 7.6%, triglycerides: 3.30 ± 1.67 mmol/l) were treated with niacin, gradually increasing the dose to 2 g/day for a total of 23 weeks. The liver fat content and visceral/subcutaneous fat was measured before and after treatment. Subjects were genotyped for the DGAT2 rs3060 and rs101899116 polymorphisms. There were significant (P < 0.001) reductions in plasma triglycerides (-34.9 ± 37.6%), liver fat content (-47.2 ± 32.8%), and visceral fat (-6.3 ± 15.8%, P < 0.05) after niacin treatment. Mean body weight decreased by 1.46 ± 2.7% (1.17 ± 2.44 kg, P < 0.001) during the study, but liver fat changes remained significant after adjustment for age, gender, and body weight changes [mean absolute change (95% CI): -6.1% (-8.0, -4.3), P < 0.001]. The DGAT2 variant alleles were associated with a smaller reduction in liver fat content in response to niacin after adjustment for other covariates (P < 0.01). These findings suggest that niacin treatment may reduce liver fat content in Chinese patients with dyslipidemia and that the mechanism may involve inhibition of DGAT2. However, the findings might have been confounded by the small but significant reductions in body weight during the study. Future large randomized controlled trials are needed to verify these findings.
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Affiliation(s)
- Miao Hu
- Departments of Medicine and Therapeutics and The Chinese University of Hong Kong, Hong Kong
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Abstract
PURPOSE OF REVIEW A lipid triad involving an atherogenic dyslipidemia characterized by moderate/high LDL-C, low HDL-C, and elevated triglyceride (TG) occurs in numerous clinical settings associated with high cardiovascular risk. This article focuses on optimizing treatment of atherogenic dyslipidemias involving this lipid triad, emphasizing niacin-based or fibrate-based therapies. RECENT FINDINGS Niacin-based therapies comprehensively improve the atherogenic lipid profile, lead to atherosclerosis regression, and exert benefits across a spectrum of cardiovascular endpoints in studies based on limited patient numbers. Fibrates impact TG, HDL-C, and LDL-C according to lipid phenotype and underlying metabolic abnormality. In a recent meta-analysis, fibrates significantly reduced major cardiovascular events (-10%) and coronary events (-13%) across a wide range of lipid phenotypes, but had no impact on stroke, sudden death, or mortality. The Action to Control Cardiovascular Risk in Diabetes (ACCORD) trial in type 2 diabetic patients similarly showed no significant effect of fenofibrate + simvastatin (vs. simvastatin) on nonfatal myocardial infarction, nonfatal stroke, or cardiovascular death; a subgroup (17%) with marked atherogenic dyslipidemia trended toward benefit. Both niacin and fibrates attenuate vascular inflammation but the potential clinical relevance is indeterminate. SUMMARY Optimal cardiovascular risk reduction in patients exhibiting the lipid triad requires integrated pharmacotherapy to normalize LDL-C, HDL-C, TGs, and potentially lipoprotein(a). Ongoing studies may provide definitive evidence of the impact of niacin plus statins on cardiovascular outcomes.
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Morey S, Mamedova L, Anderson D, Armendariz C, Titgemeyer E, Bradford B. Effects of encapsulated niacin on metabolism and production of periparturient dairy cows. J Dairy Sci 2011; 94:5090-104. [DOI: 10.3168/jds.2011-4304] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2011] [Accepted: 06/20/2011] [Indexed: 01/28/2023]
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