[Show abstract][Hide abstract] ABSTRACT: Metabolic syndrome (MetS) and insulin resistance (IR) are increasing in prevalence, are associated with higher risk for coronary heart disease (CHD), and may potentially influence the responses to lipid-altering drug therapy. This study evaluated the effects of MetS factors (abdominal obesity, depleted high-density lipoprotein cholesterol [HDL-C], and elevated triglycerides, blood pressure, and fasting glucose) and IR on ezetimibe/simvastatin and atorvastatin treatment efficacy in patients with MetS.
This post-hoc analysis of a multicenter, 6-week, double-blind, randomized, parallel group study of 1128 subjects with hypercholesterolemia, MetS, and moderately high/high CHD risk evaluated the effects of baseline MetS factors/IR on percent change from baseline in lipids, apolipoproteins, and high-sensitivity C-reactive protein (hs-CRP), after treatment with the usual starting doses of ezetimibe/simvastatin (10/20 mg) versus atorvastatin (10 mg, 20 mg) and next higher doses (10/40 mg versus 40 mg).
Ezetimibe/simvastatin and atorvastatin efficacy was generally consistent across MetS factor/IR subgroups. Ezetimibe/simvastatin produced greater incremental percent reductions in LDL-C, non-HDL-C, apolipoprotein B, total cholesterol, and lipoprotein ratios for all subgroups, and larger percent increases in HDL-C and apolipoprotein AI for all but non-obese and HDL-C ≥40 mg/dL subgroups than atorvastatin at the doses compared. Triglycerides, very-LDL-C, and hs-CRP results were more variable but similar between treatment groups.
The magnitude of lipid-altering effects produced by each treatment regimen was generally similar across all MetS and IR subgroups. Ezetimibe/simvastatin produced greater percent reductions in most lipid fractions than atorvastatin at the dose comparisons studied, and all treatments were generally well tolerated. (Registered at clinicaltrials.gov: NCT00409773).
Preview · Article · Sep 2015 · Lipids in Health and Disease
[Show abstract][Hide abstract] ABSTRACT: Non-alcoholic fatty liver (NAFLD), particularly its more aggressive form, nonalcoholic steatohepatitis (NASH), is associated with hepatic insulin resistance. Osteocalcin, a protein secreted by osteoblast cells in bone, has recently emerged as an important metabolic regulator with insulin-sensitizing properties. In humans, osteocalcin levels are inversely associated with liver disease. We thus hypothesized that osteocalcin may attenuate NASH and examined the effects of osteocalcin treatment in middle-aged (12-month-old) male Ldlr(-/-) mice, which were fed a "Western-style" high-fat, high-cholesterol diet (WHFD) for 12 weeks to induce metabolic syndrome and NASH. Mice were treated with osteocalcin (4.5ng/hr) or vehicle for the diet duration. Osteocalcin treatment not only protected against WHFD-induced insulin resistance, but substantially reduced multiple NASH components, including steatosis, ballooning degeneration, and fibrosis, with an overall reduction in NAFLD activity scores. Further, osteocalcin robustly reduced expression of pro-inflammatory and pro-fibrotic genes (Cd68, Mcp1, Spp1 and Col1a2) in liver and suppressed inflammatory gene expression in white adipose tissue. Conclusion: These results suggest osteocalcin inhibits NASH development by targeting inflammatory and fibrotic processes.
[Show abstract][Hide abstract] ABSTRACT: Adipose tissue inflammation increases with obesity, but adipocyte vs. immune cell contributions are unclear. In the present study, transcriptome analyses were performed on highly-purified subcutaneous adipocytes from lean and obese women, and differentially expressed genes/pathways were determined in both adipocyte and stromal vascular fraction (SVF) samples. Adipocyte but not SVF expression of NOD-like receptor pathway genes, including NLRP3 and PYCARD, which regulate caspase-1-mediated IL-1β secretion, correlated with adiposity phenotypes and adipocyte class II major histocompatibility complex (MHCII) gene expression, but only MHCII remained after adjusting for age and body mass index. IFNγ stimulated adipocyte MHCII, NLRP3 and caspase-1 expression, while adipocyte MHCII-mediated CD4(+) T cell activation, an important factor in adipose inflammation, induced IFNγ-dependent adipocyte IL-1β secretion. These results uncover a dialogue regulated by interactions among T cell IFNγ and adipocyte MHCII and NLRP3 inflammasome activity that appears to initiate and escalate adipose tissue inflammation during obesity.
[Show abstract][Hide abstract] ABSTRACT: Background: Impaired bioenergetics is a prominent feature of the failing heart, but the underlying metabolic perturbations are poorly understood.
Methods and Results: We compared metabolomic, gene transcript, and protein data from six paired failing human left ventricular (LV) tissue samples obtained during left ventricular assist device (LVAD) insertion (heart failure (HF) samples) and at heart transplant (post-LVAD samples). Non-failing left ventricular (NFLV) wall samples procured from explanted hearts of patients with right heart failure served as novel comparison samples. Metabolomic analyses uncovered a distinct pattern in HF tissue: increased pyruvate concentrations coupled with reduced Krebs cycle intermediates and short-chain acylcarnitines, suggesting a global reduction in substrate oxidation. These findings were associated with decreased transcript levels for enzymes that catalyze fatty acid oxidation and pyruvate metabolism and for key transcriptional regulators of mitochondrial metabolism and biogenesis, peroxisome proliferator-activated receptor gamma co-activator1α (PGC1α) and estrogen-related receptor α (ERRα) and γ (ERRγ). Thus, parallel decreases in key transcription factors and their target metabolic enzyme genes can explain the decreases in associated metabolic intermediates. Mechanical support with LVAD improved all of these metabolic and transcriptional defects.
Conclusions: These observations underscore an important pathophysiologic role for severely defective metabolism in HF, while the reversibility of these defects by LVAD suggests metabolic resilience of the human heart.
[Show abstract][Hide abstract] ABSTRACT: -Impaired bioenergetics is a prominent feature of the failing heart, but the underlying metabolic perturbations are poorly understood.
-We compared metabolomic, gene transcript, and protein data from six paired failing human left ventricular (LV) tissue samples obtained during left ventricular assist device (LVAD) insertion (heart failure (HF) samples) and at heart transplant (post-LVAD samples). Non-failing left ventricular (NFLV) wall samples procured from explanted hearts of patients with right HF served as novel comparison samples. Metabolomic analyses uncovered a distinct pattern in HF tissue: 2.6 fold increased pyruvate concentrations coupled with reduced Krebs cycle intermediates and short-chain acylcarnitines, suggesting a global reduction in substrate oxidation. These findings were associated with decreased transcript levels for enzymes that catalyze fatty acid oxidation and pyruvate metabolism and for key transcriptional regulators of mitochondrial metabolism and biogenesis, peroxisome proliferator-activated receptor gamma co-activator1α (PGC1A, 1.3 fold) and estrogen-related receptor α (ERRA, 1.2 fold) and γ (ERRG, 2.2 fold). Thus, parallel decreases in key transcription factors and their target metabolic enzyme genes can explain the decreases in associated metabolic intermediates. Mechanical support with LVAD improved all of these metabolic and transcriptional defects.
-These observations underscore an important pathophysiologic role for severely defective metabolism in HF, while the reversibility of these defects by LVAD suggests metabolic resilience of the human heart.
Full-text · Article · May 2014 · Circulation Cardiovascular Genetics
[Show abstract][Hide abstract] ABSTRACT: Clinical trials have demonstrated that it is possible to prevent diabetes through lifestyle modification, pharmacological intervention, and surgery. This review aims to summarize the effectiveness of these various therapeutic interventions in reducing the risk of progression of prediabetes to diabetes, and address the challenges to implement a diabetes prevention program at a community level. Strategies focusing on intensive lifestyle changes are not only efficient but cost-effective and/or cost-saving. Indeed, lifestyle intervention in people at high risk for type 2 diabetes mellitus (T2DM) has been successful in achieving sustained behavioral changes and a reduction in diabetes incidence even after the counseling is stopped. Although prediabetes is associated with health and economic burdens, it has not been adequately addressed by interventions or regulatory agencies in terms of prevention or disease management. Lifestyle intervention strategies to prevent T2DM should be distinct for different populations around the globe and should emphasize sex, age, ethnicity, and cultural and geographical considerations to be feasible and to promote better compliance. The translation of diabetes prevention research at a population level, especially finding the most effective methods of preventing T2DM in various societies and cultural settings remains challenging, but must be accomplished to stop this worldwide epidemic.
Preview · Article · Mar 2014 · Therapeutics and Clinical Risk Management
[Show abstract][Hide abstract] ABSTRACT: In heart failure mitochondrial dysfunction is thought to be responsible for energy depletion and contractile dysfunction. The difficulties in procuring fresh left ventricular (LV) myocardium from humans for assessment of mitochondrial function have resulted in the reliance on surrogate markers of mitochondrial function and limited our understanding of cardiac energetics. We isolated mitochondria from fresh LV wall tissue of patients with heart failure and reduced systolic function undergoing heart transplant or left ventricular assist device placement, and compared their function to mitochondria isolated from the non-failing LV (NFLV) wall tissue with normal systolic function from patients with pulmonary hypertension undergoing heart-lung transplant. We performed detailed mitochondrial functional analyses using 4 substrates: glutamate-malate (GM), pyruvate-malate (PM) palmitoyl carnitine-malate (PC) and succinate. NFLV mitochondria showed preserved respiratory control ratios and electron chain integrity with only few differences for the 4 substrates. In contrast, HF mitochondria had greater respiration with GM, PM and PC substrates and higher electron chain capacity for PM than for PC. Surprisingly, HF mitochondria had greater respiratory control ratios and lower ADP-independent state 4 rates than NFLV mitochondria for GM, PM and PC substrates demonstrating that HF mitochondria are capable of coupled respiration ex vivo. Gene expression studies revealed decreased expression of key genes in pathways for oxidation of both fatty acids and glucose. Our results suggest that mitochondria from the failing LV myocardium are capable of tightly coupled respiration when isolated and supplied with ample substrates. Thus energy starvation in the failing heart may be the result of dysregulation of metabolic pathways, impaired substrate supply or reduced mitochondrial number but not the result of reduced mitochondrial electron transport capacity.
No preview · Article · Jan 2014 · Journal of Molecular and Cellular Cardiology
[Show abstract][Hide abstract] ABSTRACT: Treatment response to lipid-lowering therapy can vary in patients with the metabolic syndrome (MetS) due to various patient demographic and baseline characteristics.
This study assessed the relationships between baseline characteristics and changes in lipid variables, high-sensitivity C-reactive protein (hs-CRP) and attainment of prespecified low-density lipoprotein cholesterol (LDL-C) and non-high-density lipoprotein cholesterol (non-HDL-C) levels in MetS patients treated with ezetimibe/simvastatin and atorvastatin.
This is a post-hoc analysis of a multicenter, double-blind, randomized, 6-week parallel study in >1000 hypercholesterolemic subjects (median age of 59 years) with MetS and moderately high/high coronary heart disease risk who were treated with ezetimibe/simvastatin (10/20 and 10/40 mg) or atorvastatin (10, 20, 40 mg). Factors that could affect these treatments were assessed by multivariate analysis.
Increasing age, abdominal obesity (waist circumference ≥40/35 inches for men/women), and lower baseline hs-CRP were significant predictors of greater reductions in LDL-C, non-HDL-C, apolipoprotein B, total cholesterol, triglycerides, and very-low-density lipoprotein cholesterol but not for changes in HDL-C or apolipoprotein AI; effects of race and baseline triglycerides, non-HDL-C, LDL-C, or HDL-C levels were more limited. Age ≥65 years (versus <65 years) was also associated with significantly greater attainment of all LDL-C and non-HDL-C targets, whereas abdominal obesity, gender (female > male) and lower baseline LDL-C, non-HDL-C, triglycerides, and hs-CRP were associated with improved attainment for some of these targets. Blood pressure, fasting glucose, Homeostasis Model Assessment of Insulin Resistance tertiles, and diabetes did not predict response for any efficacy variable. Ezetimibe/simvastatin treatment (versus atorvastatin) was a significant predictor for change in most efficacy variables.
Treatment responses to ezetimibe/simvastatin and atorvastatin in at-risk patients with the MetS were related to age (≥65 years), abdominal obesity, and lower baseline hs-CRP. Ezetimibe/simvastatin treatment was found to be consistently more effective than atorvastatin at the specified dose comparisons across these subgroups. The clinical value of predictive factors requires further study in outcome trials.
No preview · Article · Jul 2013 · Journal of Clinical Lipidology
[Show abstract][Hide abstract] ABSTRACT: PPARγ nuclear receptor agonists have been shown to attenuate macrophage inflammatory responses implicated in the metabolic complications of obesity and in atherosclerosis. However, PPARγ agonists currently in clinical use, including rosiglitazone (RSG), are often associated with severe side effects that limit their therapeutic use. Here, 200 nm PLGA/PVA nanospheres were formulated for the systemic delivery of RSG specifically to macrophages. RSG was encapsulated with over 50% efficiency in the hydrophobic PLGA core and released specifically within the acidifying macrophage phagosomes. In bone marrow derived macrophages, RSG-loaded nanoparticles (RSG-NPs) induce a dose dependent upregulation (1.5 to 2.5-fold) of known PPARγ target genes, with maximal induction at 5 μM; and downregulate the expression of genes related to the inflammatory process, with maximum effect at 10 μM. In Ldlr(-/-) mice fed high fat diet, treatment with RSG-NPs alleviated inflammation in white adipose tissue and liver but, unlike treatment with free RSG, did not alter genes associated with lipid metabolism or cardiac function, indicating a reduction in the RSG side effect profile. These biocompatible, biodegradable RSG-NPs represent a preliminary step towards the specific delivery of nuclear receptor agonists for the treatment of macrophage-mediated inflammatory conditions associated with obesity, atherosclerosis and other chronic disease states.
No preview · Article · Jun 2013 · Journal of Controlled Release
[Show abstract][Hide abstract] ABSTRACT: The worldwide prevalence of obesity mandates a widely accessible tool to categorize adiposity that can best predict associated health risks. The body adiposity index (BAI) was designed as a single equation to predict body adiposity in pooled analysis of both genders. We compared body adiposity index (BAI), body mass index (BMI), and other anthropometric measures, including percent body fat (PBF), in their correlations with cardiometabolic risk factors. We also compared BAI with BMI to determine which index is a better predictor of PBF.
[Show abstract][Hide abstract] ABSTRACT: In obesity, reduced cardiac glucose uptake and mitochondrial abnormalities are putative causes of cardiac dysfunction. However, high fat diet (HFD) does not consistently induce cardiac insulin resistance and mitochondrial damage, and recent studies suggest HFD may be cardioprotective. To determine cardiac responses to HFD, we investigated cardiac function, glucose uptake and mitochondrial respiration in young (3-month-old) and middle-aged (MA; 12-month-old) male Ldlr(-/-) mice fed chow or 3 months HFD to induce obesity, systemic insulin resistance and hyperinsulinemia. In MA Ldlr(-/-) mice, HFD induced accelerated atherosclerosis and nonalcoholic steatohepatitis, common complications of human obesity. Surprisingly, HFD-fed mice demonstrated increased cardiac glucose uptake, which was most prominent in MA mice, in the absence of cardiac contractile dysfunction or hypertrophy. Moreover, hearts of HFD-fed mice had enhanced mitochondrial oxidation of palmitoyl carnitine, glutamate, and succinate, and greater basal insulin signaling compared to those of chow-fed mice, suggesting cardiac insulin sensitivity was maintained, despite systemic insulin resistance. Streptozotocin (STZ)-induced ablation of insulin production markedly reduced cardiac glucose uptake and mitochondrial dysfunction in HFD-fed, but not in chow-fed mice. Insulin injection reversed these effects, suggesting that insulin may protect cardiac mitochondria during HFD. These results have implications for cardiac metabolism and preservation of mitochondrial function in obesity.
[Show abstract][Hide abstract] ABSTRACT: Aims/hypothesis:
Insulin clearance is a highly heritable trait, for which few quantitative trait loci have been discovered. We sought to determine whether validated type 2 diabetes and/or glycaemic trait loci are associated with insulin clearance.
Hyperinsulinaemic-euglycaemic clamps were performed in two Hispanic-American family cohorts totalling 1329 participants in 329 families. The Metabochip was used to fine-map about 50 previously identified loci for type 2 diabetes, fasting glucose, fasting insulin, 2 h glucose or HbA1c. This resulted in 17,930 variants, which were tested for association with clamp-derived insulin clearance via meta-analysis of the two cohorts.
In the meta-analysis, 38 variants located within seven loci demonstrated association with insulin clearance (p < 0.001). The top signals for each locus were rs10241087 (DGKB/TMEM195 [TMEM195 also known as AGMO]) (p = 4.4 × 10(-5)); chr1:217605433 (LYPLAL1) (p = 3.25 × 10(-4)); rs2380949 (GLIS3) (p = 3.4 × 10(-4)); rs55903902 (FADS1) (p = 5.6 × 10(-4)); rs849334 (JAZF1) (p = 6.4 × 10(-4)); rs35749 (IGF1) (p = 6.7 × 10(-4)); and rs9460557 (CDKAL1) (p = 6.8 × 10(-4)).
While the majority of validated loci for type 2 diabetes and related traits do not appear to influence insulin clearance in Hispanics, several of these loci do show evidence of association with this trait. It is therefore possible that these loci could have pleiotropic effects on insulin secretion, insulin sensitivity and insulin clearance.
[Show abstract][Hide abstract] ABSTRACT: Tissue oxidative stress is a common hallmark of atherosclerosis and non-alcoholic steatohepatitis (NASH), 2 conditions linked epidemiologically and pathophysiologically. Nuclear factor (erythroid-derived 2)-like 2 (Nrf2) is the master regulator of inducible antioxidant responses, that can attenuate cellular injury from oxidative stress induced by obesity and other redox insults. Nrf2 expression and activation is reduced in mouse and human vessels that harbor accelerated atherosclerosis and in livers with histologic criteria of NASH. Systemic antioxidants have thus been attractive therapeutic targets, but clinical trials have been largely unsuccessful in improving cardiovascular health. Macrophage-selective Nrf2 activation may, however, provide an approach to reduce vascular and hepatocyte injury without the complications of systemic antioxidants, since macrophages play key roles in the development and progression of both atherosclerosis and NASH. In this article, we review the common mechanisms of oxidative stress and inflammation in atherosclerosis and NASH, and discuss the role of Nrf2 in vascular and hepatocyte protection.
No preview · Article · Mar 2013 · Current Diabetes Reports
[Show abstract][Hide abstract] ABSTRACT: Adipose-resident T cells (ARTs) regulate metabolic and inflammatory responses in obesity, but ART activation signals are poorly understood. Here, we describe class II major histocompatibility complex (MHCII) as an important component of high-fat-diet (HFD)-induced obesity. Microarray analysis of primary adipocytes revealed that multiple genes involved in MHCII antigen processing and presentation increased in obese women. In mice, adipocyte MHCII increased within 2 weeks on HFD, paralleling increases in proinflammatory ART markers and decreases in anti-inflammatory ART markers, and preceding adipose tissue macrophage (ATM) accumulation and proinflammatory M1 polarization. Mouse 3T3-L1 and primary adipocytes activated T cells in an antigen-specific, contact-dependent manner, indicating that adipocyte MHCII is functional. HFD-fed MHCII mice developed less adipose inflammation and insulin resistance than did wild-type mice, despite developing similar adiposity. These investigations uncover a mechanism whereby a HFD-induced adipocyte/ART dialog involving MHCII instigates adipose inflammation and, together with ATM MHCII, escalates its progression.
[Show abstract][Hide abstract] ABSTRACT: Inflammasomes are a family of protein complexes that recognize diverse microbial and endogenous danger signals to promote innate immune responses, tissue inflammation and injury, or cell death via pyroptosis. Inflammasome activation results in the recruitment and activation of caspase-1, which is required for the production of the proinflammatory cytokines interleukin-1β (IL-1β) and IL-18 that can modulate both adaptive and innate immune responses through effects on leukocyte survival, proliferation, differentiation, and migration. Recent studies suggest that inflammasome activity may also play important roles in several nonmicrobial disease states associated with chronic inflammation. For example, NLRP3 inflammasome expression and IL-1β production are both increased in obesity, and recent work has implicated NLRP3 inflammasome activation in a variety of obesity-linked conditions including gout, type 2 diabetes mellitus, metabolic liver disease, atherosclerosis, Alzheimer’s disease, cancer and rheumatoid arthritis. Further, many of the factors associated with these conditions, including elevated plasma glucose, fatty acids, uric acid and cholesterol crystals, and β-amyloid, have been shown to be elevated during obesity and to stimulate NLRP3 inflammasome expression or activation. Since chronic NLRP3 activation appears to play important roles in several common disease states, better understanding of inflammasome regulation and function may lead to better therapeutic approaches. Several agents that attenuate NLRP3 inflammasome activity or inhibit its primary effector, IL-1β, are currently under development or in early clinical trials as therapeutics to treat these common disease conditions. This chapter will review new research on inflammasome activation, its role in obesity and other chronic inflammatory states, and the status of approaches to attenuate NLRP3 inflammasome activity.
[Show abstract][Hide abstract] ABSTRACT: The majority of cholesterol reduction therapies, such as the statin drugs, work primarily by inducing the expression of hepatic low-density lipoprotein receptors (LDLRs), rendering these therapeutics only partially effective in animals lacking LDLRs. Although thyroid hormones and their synthetic derivatives, often referred to as thyromimetics, have been clearly shown to reduce serum cholesterol levels, this action has generally been attributed to their ability to increase expression of hepatic LDLRs. Here we show for the first time that the thyroid hormone T(3) and the thyroid hormone receptor-β selective agonists GC-1 and KB2115 are capable of markedly reducing serum cholesterol in mice devoid of functional LDLRs by inducing Cyp7a1 expression and stimulating the conversion and excretion of cholesterol as bile acids. Based on this LDLR-independent mechanism, thyromimetics such as GC-1 and KB2115 may represent promising cholesterol-lowering therapeutics for the treatment of diseases such as homozygous familial hypercholesterolemia, a rare genetic disorder caused by a complete lack of functional LDLRs, for which there are limited treatment options because most therapeutics are only minimally effective.
[Show abstract][Hide abstract] ABSTRACT: Abstract Objective: BP-CRUSH (Blood Pressure Control in All Subgroups With Hypertension) was a phase IV, prospective, open-label, multicenter, single-arm, dose-titration study (N=999). The present subgroup analysis reports the efficacy/safety of up to 20 weeks' treatment with amlodipine (AML)/olmesartan medoxomil (OM) ± hydrochlorothiazide (HCTZ) in obese and non-obese patients with hypertension uncontrolled on antihypertensive monotherapy. Research Design and Methods: Eligible obese (body mass index ≥30 kg/m(2); n=505) and non-obese (<30 kg/m(2); n=494) patients were switched to AML/OM 5/20 mg and uptitrated at 4-week intervals to AML/OM 5/40 mg, AML/OM 10/40 mg, AML/OM 10/40 mg + HCTZ 12.5 mg, and AML/OM 10/40 mg + HCTZ 25 mg. Uptitration to higher doses of AML/OM was permitted if mean seated systolic BP (SeSBP) was ≥120 mmHg, or mean seated diastolic BP (SeDBP) was ≥70 mmHg. HCTZ was added if mean SeSBP was ≥125 mmHg, or mean SeDBP was ≥75 mmHg. Clinical Trial Registration: ClinicalTrials.gov identifier: NCT00791258 Main Outcome Measures: The primary efficacy endpoint was the cumulative proportion of patients achieving SeSBP <140 mmHg (<130 mmHg for patients with diabetes) at 12 weeks. Secondary endpoints included SeBP goal rates, ambulatory BP target rates, and mean change from baseline in SeBP and ambulatory BP at Weeks 12 and 20. Results: At 12 weeks, 71.6% of obese patients (80.2% non-obese) achieved the primary endpoint of cumulative SeSBP <140 mmHg (<130 mmHg for patients with diabetes). The cumulative SeBP goal of <140/90 mmHg (<130/80 mmHg if diabetes) was achieved by 64.8% and 81.2% of obese patients by Weeks 12 and 20, respectively (vs. 77.9% and 88.5% of non-obese patients, respectively). Treatment was well tolerated, with 26.1% of obese patients (24.9% non-obese) experiencing treatment-emergent drug-related adverse events (none serious). Conclusion: An AML/OM ± HCTZ treatment regimen provided effective and safe BP control in obese patients with hypertension uncontrolled on monotherapy.
No preview · Article · Oct 2012 · Current Medical Research and Opinion
[Show abstract][Hide abstract] ABSTRACT: Objective:
To determine the impact of hematopoietic deletion of nuclear factor- (erythroid-derived 2) like 2 factor (Nrf2) on the development of atherosclerosis and liver injury in an obese, hypercholesterolemic mouse model.
Methods and results:
Two-month-old male low-density lipoprotein receptor-deficient mice were lethally irradiated and transplanted with either wild type or Nrf2-deficient (Nrf2(-/-)) bone marrow cells. At 3 months of age, mice were placed on an obesogenic high-fat diet (HFD), high-cholesterol diet for 7 months. Despite no differences in body weight, body fat percentage, liver fat, plasma glucose, lipids, or insulin, the HFD-fed Nrf2(-/-) bone marrow recipients had increased proinflammatory vascular gene expression, a significant increase in atherosclerosis area (18% versus 28%; P=0.018) and lesion complexity, and a marked increase in liver fibrosis. The acceleration of vascular and liver injury may arise from enhanced macrophage migration, inflammation, and oxidative stress resulting from myeloid Nrf2 deficiency.
Myeloid-derived Nrf2 activity attenuates atherosclerosis development and liver inflammation and fibrosis associated with obesity. Prevention of oxidative stress in macrophage and other myeloid lineage cells may be an important therapeutic target to reduce inflammation-driven complications of obesity.
[Show abstract][Hide abstract] ABSTRACT: We developed a multinomial ordinal probit model with singular value decomposition for testing a large number of single nucleotide polymorphisms (SNPs) simultaneously for association with multidisease status when sample size is much smaller than the number of SNPs. The validity and performance of the method was evaluated via simulation. We applied the method to our real study sample recruited through the Mexican-American Coronary Artery Disease study. We found 3 genes (SORCS1, AMPD1, and PPAR
) to be associated with the development of both IGT and IFG, while 5 genes (AMPD2, PRKAA2, C5, TCF7L2, and ITR) with the IGT mechanism only and 6 genes (CAPN10, IL4, NOS3, CD14, GCG, and SORT1) with the IFG mechanism only. These data suggest that IGT and IFG may indicate different physiological mechanism to prediabetes, via different genetic determinants.
Full-text · Article · Sep 2012 · Journal of Probability and Statistics