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Publication
Journal: International journal of obesity and related metabolic disorders : journal of the International Association for the Study of Obesity
September/9/1992
Abstract
The medical effects of modest weight reduction (approximately 10% or less) in patients with obesity-associated medical complications were reviewed. The National Library of Medicine MEDLINE database and the Derwent RINGDOC database were searched to identify English language studies that examined the effects of weight loss in obese patients with serious medical complications commonly associated with obesity (non-insulin dependent diabetes mellitus (NIDDM or type II), hypertension, hyperlipidemia, hypercholesterolemia, and cardiovascular disease). Studies in which patients experienced approximately 10% or less weight reduction were selected for review. Studies indicated that, for obese patients with NIDDM, hypertension or hyperlipidemia, modest weight reduction appeared to improve glycemic control, reduce blood pressure, and reduce cholesterol levels, respectively. Modest weight reduction also appeared to increase longevity in obese individuals. In conclusion, a large proportion of obese individuals with NIDDM, hypertension, and hyperlipidemia experienced positive health benefits with modest weight loss. For patients who are unable to attain and maintain substantial weight reduction, modest weight loss should be recommended; even a small amount of weight loss appears to benefit a substantial subset of obese patients.
Publication
Journal: Archives of pediatrics & adolescent medicine
January/25/2010
Abstract
OBJECTIVE
To understand why children exposed to adverse psychosocial experiences are at elevated risk for age-related disease, such as cardiovascular disease, by testing whether adverse childhood experiences predict enduring abnormalities in stress-sensitive biological systems, namely, the nervous, immune, and endocrine/metabolic systems.
METHODS
A 32-year prospective longitudinal study of a representative birth cohort.
METHODS
New Zealand.
METHODS
A total of 1037 members of the Dunedin Multidisciplinary Health and Development Study. Main Exposures During their first decade of life, study members were assessed for exposure to 3 adverse psychosocial experiences: socioeconomic disadvantage, maltreatment, and social isolation.
METHODS
At age 32 years, study members were assessed for the presence of 3 age-related-disease risks: major depression, high inflammation levels (high-sensitivity C-reactive protein level >3 mg/L), and the clustering of metabolic risk biomarkers (overweight, high blood pressure, high total cholesterol, low high-density lipoprotein cholesterol, high glycated hemoglobin, and low maximum oxygen consumption levels.
RESULTS
Children exposed to adverse psychosocial experiences were at elevated risk of depression, high inflammation levels, and clustering of metabolic risk markers. Children who had experienced socioeconomic disadvantage (incidence rate ratio, 1.89; 95% confidence interval, 1.36-2.62), maltreatment (1.81; 1.38-2.38), or social isolation (1.87; 1.38-2.51) had elevated age-related-disease risks in adulthood. The effects of adverse childhood experiences on age-related-disease risks in adulthood were nonredundant, cumulative, and independent of the influence of established developmental and concurrent risk factors.
CONCLUSIONS
Children exposed to adverse psychosocial experiences have enduring emotional, immune, and metabolic abnormalities that contribute to explaining their elevated risk for age-related disease. The promotion of healthy psychosocial experiences for children is a necessary and potentially cost-effective target for the prevention of age-related disease.
Publication
Journal: Nature Genetics
June/5/2007
Abstract
Resequencing genes provides the opportunity to assess the full spectrum of variants that influence complex traits. Here we report the first application of resequencing to a large population (n = 3,551) to examine the role of the adipokine ANGPTL4 in lipid metabolism. Nonsynonymous variants in ANGPTL4 were more prevalent in individuals with triglyceride levels in the lowest quartile than in individuals with levels in the highest quartile (P = 0.016). One variant (E40K), present in approximately 3% of European Americans, was associated with significantly lower plasma levels of triglyceride and higher levels of high-density lipoprotein cholesterol in European Americans from the Atherosclerosis Risk in Communities Study and in Danes from the Copenhagen City Heart Study. The ratio of nonsynonymous to synonymous variants was higher in European Americans than in African Americans (4:1 versus 1.3:1), suggesting population-specific relaxation of purifying selection. Thus, resequencing of ANGPTL4 in a multiethnic population allowed analysis of the phenotypic effects of both rare and common variants while taking advantage of genetic variation arising from ethnic differences in population history.
Publication
Journal: Arteriosclerosis, Thrombosis, and Vascular Biology
December/6/2001
Abstract
The 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors or statins are potent inhibitors of cholesterol biosynthesis. Several large clinical trials have demonstrated the beneficial effects of statins in the primary and secondary prevention of coronary heart disease. However, the overall clinical benefits observed with statin therapy appear to be greater than what might be expected from changes in lipid profile alone, suggesting that the beneficial effects of statins may extend beyond their effects on serum cholesterol levels. Indeed, recent experimental and clinical evidence indicates that some of the cholesterol-independent or "pleiotropic" effects of statins involve improving or restoring endothelial function, enhancing the stability of atherosclerotic plaques, and decreasing oxidative stress and vascular inflammation. Many of these pleiotropic effects of statins are mediated by their ability to block the synthesis of important isoprenoid intermediates, which serve as lipid attachments for a variety of intracellular signaling molecules. In particular, the inhibition of small GTP-binding proteins, Rho, Ras, and Rac, whose proper membrane localization and function are dependent on isoprenylation, may play an important role in mediating the direct cellular effects of statins on the vascular wall.
Publication
Journal: Proceedings of the National Academy of Sciences of the United States of America
September/20/2007
Abstract
In the fasted state, induction of hepatic glucose output and fatty acid oxidation is essential to sustain energetic balance. Production and oxidation of glucose and fatty acids by the liver are controlled through a complex network of transcriptional regulators. Among them, the transcriptional coactivator PGC-1alpha plays an important role in hepatic and systemic glucose and lipid metabolism. We have previously demonstrated that sirtuin 1 (SIRT1) regulates genes involved in gluconeogenesis through interaction and deacetylation of PGC-1alpha. Here, we show in vivo that hepatic SIRT1 is a factor in systemic and hepatic glucose, lipid, and cholesterol homeostasis. Knockdown of SIRT1 in liver caused mild hypoglycemia, increased systemic glucose and insulin sensitivity, and decreased glucose production. SIRT1 knockdown also decreased serum cholesterol and increased hepatic free fatty acid and cholesterol content. These metabolic phenotypes caused by SIRT1 knockdown tightly correlated with decreased expression of gluconeogenic, fatty acid oxidation and cholesterol degradation as well as efflux genes. Additionally, overexpression of SIRT1 reversed many of the changes caused by SIRT1 knockdown and depended on the presence of PGC-1alpha. Interestingly, most of the effects of SIRT1 were only apparent in the fasted state. Our results indicate that hepatic SIRT1 is an important factor in the regulation of glucose and lipid metabolism in response to nutrient deprivation. As these pathways are dysregulated in metabolic diseases, SIRT1 may be a potential therapeutic target to control hyperglycemia and hypercholesterolemia.
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Publication
Journal: Diabetes Care
June/8/1997
Abstract
OBJECTIVE
To assess in diabetic patients with coronary heart disease (CHD) the effect of cholesterol lowering with simvastatin on mortality and the risk of CHD and other atherosclerotic events.
METHODS
A post hoc subgroup analysis was carried out on data from 202 diabetic patients and 4,242 nondiabetic patients with previous myocardial infarction or angina pectoris, serum total cholesterol 5.5-8.0 mmol/l, and serum triglycerides < or = 2.5 mmol/l who were participating in the Scandinavian Simvastatin Survival Study (4S). Participants in the 4S were randomly assigned to double-blind treatment with simvastatin, 20 mg daily, with blinded dosage titration up to 40 mg daily, according to cholesterol response during the first 6-18 weeks, or placebo. Endpoints were 1) total mortality, 2) major CHD events (CHD death or nonfatal myocardial infarction), 3) other acute atherosclerotic events, 4) myocardial revascularization procedures.
RESULTS
Over the 5.4-year median follow-up period, simvastatin treatment produced mean changes in serum lipids in diabetic patients similar to those observed in nondiabetic patients. The relative risks (RRs) of main endpoints in simvastatin-treated diabetic patients were as follows: total mortality 0.57 (95% CI, 0.30-1.08; P = 0.087), major CHD events 0.45 (95% CI, 0.27-0.74; P = 0.002), and any atherosclerotic event 0.63 (95% CI, 0.43-0.92; P = 0.018). The corresponding RRs in nondiabetic patients were the following: 0.71 (95% CI, 0.58-0.87; P = 0.001), 0.68 (95% CI, 0.60-0.77; P < 0.0001), and 0.74 (95% CI, 0.68-0.82; P < 0.0001).
CONCLUSIONS
The results strongly suggest that cholesterol lowering with simvastatin improves the prognosis of diabetic patients with CHD. The absolute clinical benefit achieved by cholesterol lowering may be greater in diabetic than in nondiabetic patients with CHD because diabetic patients have a higher absolute risk of recurrent CHD events and other atherosclerotic events.
Publication
Journal: BMJ (Clinical research ed.)
January/20/2000
Abstract
OBJECTIVE
To summarise quantitatively the association between moderate alcohol intake and biological markers of risk of coronary heart disease and to predict how these changes would lower the risk.
METHODS
Meta-analysis of all experimental studies that assessed the effects of moderate alcohol intake on concentrations of high density lipoprotein cholesterol, apolipoprotein A I, fibrinogen, triglycerides, and other biological markers previously found to be associated with risk of coronary heart disease.
METHODS
Men and women free of previous chronic disease and who were not dependent on alcohol. Studies were included in which biomarkers were assessed before and after participants consumed up to 100 g of alcohol a day.
METHODS
Alcohol as ethanol, beer, wine, or spirits.
METHODS
Changes in concentrations of high density lipoprotein cholesterol, apolipoprotein A I, Lp(a) lipoprotein, triglycerides, tissue type plasminogen activator activity, tissue type plasminogen activator antigen, insulin, and glucose after consuming an experimental dose of alcohol for 1 to 9 weeks; a shorter period was accepted for studies of change in concentrations of fibrinogen, factor VII, von Willebrand factor, tissue type plasminogen activator activity, and tissue type plasminogen activator antigen.
RESULTS
61 data records were abstracted from 42 eligible studies with information on change in biological markers of risk of coronary heart disease. An experimental dose of 30 g of ethanol a day increased concentrations of high density lipoprotein cholesterol by 3.99 mg/dl (95% confidence interval 3.25 to 4.73), apolipoprotein A I by 8.82 mg/dl (7.79 to 9.86), and triglyceride by 5.69 mg/dl (2.49 to 8.89). Several haemostatic factors related to a thrombolytic profile were modestly affected by alcohol. On the basis of published associations between these biomarkers and risk of coronary heart disease 30 g of alcohol a day would cause an estimated reduction of 24.7% in risk of coronary heart disease.
CONCLUSIONS
Alcohol intake is causally related to lower risk of coronary heart disease through changes in lipids and haemostatic factors.
Publication
Journal: Nature
August/12/2013
Abstract
The mechanistic target of rapamycin (mTOR) pathway integrates diverse environmental inputs, including immune signals and metabolic cues, to direct T-cell fate decisions. The activation of mTOR, which is the catalytic subunit of the mTORC1 and mTORC2 complexes, delivers an obligatory signal for the proper activation and differentiation of effector CD4(+) T cells, whereas in the regulatory T-cell (T(reg)) compartment, the Akt-mTOR axis is widely acknowledged as a crucial negative regulator of T(reg)-cell de novo differentiation and population expansion. However, whether mTOR signalling affects the homeostasis and function of T(reg) cells remains largely unexplored. Here we show that mTORC1 signalling is a pivotal positive determinant of T(reg)-cell function in mice. T(reg) cells have elevated steady-state mTORC1 activity compared to naive T cells. Signals through the T-cell antigen receptor (TCR) and interleukin-2 (IL-2) provide major inputs for mTORC1 activation, which in turn programs the suppressive function of T(reg) cells. Disruption of mTORC1 through Treg-specific deletion of the essential component raptor leads to a profound loss of T(reg)-cell suppressive activity in vivo and the development of a fatal early onset inflammatory disorder. Mechanistically, raptor/mTORC1 signalling in T(reg) cells promotes cholesterol and lipid metabolism, with the mevalonate pathway particularly important for coordinating T(reg)-cell proliferation and upregulation of the suppressive molecules CTLA4 and ICOS to establish Treg-cell functional competency. By contrast, mTORC1 does not directly affect the expression of Foxp3 or anti- and pro-inflammatory cytokines in T(reg) cells, suggesting a non-conventional mechanism for T(reg)-cell functional regulation. Finally, we provide evidence that mTORC1 maintains T(reg)-cell function partly through inhibiting the mTORC2 pathway. Our results demonstrate that mTORC1 acts as a fundamental 'rheostat' in T(reg) cells to link immunological signals from TCR and IL-2 to lipogenic pathways and functional fitness, and highlight a central role of metabolic programming of T(reg)-cell suppressive activity in immune homeostasis and tolerance.
Publication
Journal: The Lancet
November/27/2000
Abstract
BACKGROUND
Cardiovascular disease rates vary greatly between ethnic groups in Canada. To establish whether this variation can be explained by differences in disease risk factors and subclinical atherosclerosis, we undertook a population-based study of three ethnic groups in Canada: South Asians, Chinese, and Europeans.
METHODS
985 participants were recruited from three cities (Hamilton, Toronto, and Edmonton) by stratified random sampling. Clinical cardiovascular disease was defined by history or electrocardiographic findings. Carotid atherosclerosis was measured with B-mode ultrasonography. Conventional (smoking, hypertension, diabetes, raised cholesterol) and novel risk factors (markers of a prothrombotic state) were measured.
RESULTS
Within each ethnic group and overall, the degree of carotid atherosclerosis was associated with a higher prevalence of cardiovascular disease. South Asians had the highest prevalence of this condition compared with Europeans and Chinese (11%, 5%, and 2%, respectively, p=0.0004). Despite this finding, Europeans had more atherosclerosis (mean of the maximum intimal medial thickness 0.75 [0.16] mm) than South Asians (0.72 [0.15] mm), and Chinese (0.69 [0.16] mm). South Asians had an increased prevalence of glucose intolerance, higher total and LDL cholesterol, higher triglycerides, and lower HDL cholesterol, and much greater abnormalities in novel risk factors including higher concentrations of fibrinogen, homocysteine, lipoprotein (a), and plasminogen activator inhibitor-1.
CONCLUSIONS
Although there are differences in conventional and novel risk factors between ethnic groups, this variation and the degree of atherosclerosis only partly explains the higher rates of cardiovascular disease among South Asians compared with Europeans and Chinese. The increased risk of cardiovascular events could be due to factors affecting plaque rupture, the interaction between prothrombotic factors and atherosclerosis, or as yet undiscovered risk factors.
Publication
Journal: Hepatology
October/3/2017
Abstract
Noncoding RNAs play important roles in cancer biology, providing potential targets for cancer intervention. As a new class of endogenous noncoding RNAs, circular RNAs (circRNAs) have been recently identified in cell development and function, and certain types of pathological responses, generally acting as a microRNA (miRNA) sponge to regulate gene expression. Identifying the deregulated circRNAs and their roles in cancer has attracted much attention. However, the expression profile and function of circRNAs in human hepatocellular carcinoma (HCC) remain to be investigated. Here, we analyzed the expression profile of human circRNAs in HCC tissues and identified circMTO1 (mitochondrial translation optimization 1 homologue; hsa_circRNA_0007874/hsa_circRNA_104135) as one circRNA significantly down-regulated in HCC tissues. HCC patients with low circMTO1 expression had shortened survival. By using a biotin-labeled circMTO1 probe to perform RNA in vivo precipitation in HCC cells, we identified miR-9 as the circMTO1-associated miRNA. Furthermore, silencing of circMTO1 in HCC could down-regulate p21, the target of oncogenic miR-9, resulting in the promotion of HCC cell proliferation and invasion. In addition, the tumor-promoting effect of circMTO1 silencing was blocked by miR9 inhibitor. Intratumoral administration of cholesterol-conjugated circMTO1 small interfering RNA promoted tumor growth in HCC-bearing mice in vivo.
circMTO1 suppresses HCC progression by acting as the sponge of oncogenic miR-9 to promote p21 expression, suggesting that circMTO1 is a potential target in HCC treatment. The decrease of circMTO1 in HCC tissues may serve as a prognosis predictor for poor survival of patients. (Hepatology 2017;66:1151-1164).
Publication
Journal: Circulation
September/26/1979
Abstract
The hypothesis that plasma chylomicrons in persons who ingest a cholesterol-rich diet are atherogenic is evaluated. Evidence is presented that in humans, and experimental animals, chylomicron remnants as well as low-density lipoproteins are taken up by arterial cells. In persons who do not have familial hyperlipoproteinemia, atherogenesis may occur during the postprandial period. Research directions that may contribute to the evaluation of chylomicron remnants as a risk factor for atherogenesis are discussed. Lipoprotein studies after administration of a test meal containing fat and cholesterol are urgently needed.
Publication
Journal: Journal of Clinical Investigation
June/7/2009
Abstract
Hepatic steatosis is present in insulin-resistant obese rodents and is concomitant with active lipogenesis. Hepatic lipogenesis depends on the insulin-induced activation of the transcription factor SREBP-1c. Despite prevailing insulin resistance, SREBP-1c is activated in the livers of genetically and diet-induced obese rodents. Recent studies have reported the presence of an ER stress response in the livers of obese ob/ob mice. To assess whether ER stress promotes SREBP-1c activation and thus contributes to lipogenesis, we overexpressed the chaperone glucose-regulated protein 78 (GRP78) in the livers of ob/ob mice using an adenoviral vector. GRP78 overexpression reduced ER stress markers and inhibited SREBP-1c cleavage and the expression of SREBP-1c and SREBP-2 target genes. Furthermore, hepatic triglyceride and cholesterol contents were reduced, and insulin sensitivity improved, in GRP78-injected mice. These metabolic improvements were likely mediated by restoration of IRS-2 expression and tyrosine phosphorylation. Interestingly, GRP78 overexpression also inhibited insulin-induced SREBP-1c cleavage in cultured primary hepatocytes. These findings demonstrate that GRP78 inhibits both insulin-dependent and ER stress-dependent SREBP-1c proteolytic cleavage and explain the role of ER stress in hepatic steatosis in obese rodents.
Publication
Journal: JAMA - Journal of the American Medical Association
September/20/2004
Abstract
BACKGROUND
Limited data are available evaluating how the timing and intensity of statin therapy following an acute coronary syndrome (ACS) event affect clinical outcome.
OBJECTIVE
To compare early initiation of an intensive statin regimen with delayed initiation of a less intensive regimen in patients with ACS.
METHODS
International, randomized, double-blind trial of patients with ACS receiving 40 mg/d of simvastatin for 1 month followed by 80 mg/d thereafter (n = 2265) compared with ACS patients receiving placebo for 4 months followed by 20 mg/d of simvastatin (n = 2232), who were enrolled in phase Z of the A to Z trial between December 29, 1999, and January 6, 2003.
METHODS
The primary end point was a composite of cardiovascular death, nonfatal myocardial infarction, readmission for ACS, and stroke. Follow-up was for at least 6 months and up to 24 months.
RESULTS
Among the patients in the placebo plus simvastatin group, the median low-density lipoprotein (LDL) cholesterol level achieved while taking placebo was 122 mg/dL (3.16 mmol/L) at 1 month and was 77 mg/dL (1.99 mmol/L) at 8 months while taking 20 mg/d of simvastatin. Among the patients in the simvastatin only group, the median LDL cholesterol level achieved at 1 month while taking 40 mg/d of simvastatin was 68 mg/dL (1.76 mmol/L) and was 63 mg/dL (1.63 mmol/L) at 8 months while taking 80 mg/d of simvastatin. A total of 343 patients (16.7%) in the placebo plus simvastatin group experienced the primary end point compared with 309 (14.4%) in the simvastatin only group (40 mg/80 mg) (hazard ratio [HR], 0.89; 95% confidence interval [CI] 0.76-1.04; P =.14). Cardiovascular death occurred in 109 (5.4%) and 83 (4.1%) patients in the 2 groups (HR, 0.75; 95% CI, 0.57-1.00; P =.05) but no differences were observed in other individual components of the primary end point. No difference was evident during the first 4 months between the groups for the primary end point (HR, 1.01; 95% CI, 0.83-1.25; P =.89), but from 4 months through the end of the study the primary end point was significantly reduced in the simvastatin only group (HR, 0.75; 95% CI, 0.60-0.95; P =.02). Myopathy (creatine kinase >10 times the upper limit of normal associated with muscle symptoms) occurred in 9 patients (0.4%) receiving simvastatin 80 mg/d, in no patients receiving lower doses of simvastatin, and in 1 patient receiving placebo (P =.02).
CONCLUSIONS
The trial did not achieve the prespecified end point. However, among patients with ACS, the early initiation of an aggressive simvastatin regimen resulted in a favorable trend toward reduction of major cardiovascular events.
Publication
Journal: Traffic
June/24/2004
Abstract
An expression screen of a rat cDNA library for sequences encoding Golgi-localized integral membrane proteins identified a protein with an apparent novel topology, i.e. with both an N-terminal transmembrane domain and a C-terminal glycosyl-phosphatidylinositol (GPI) anchor. Our data are consistent with this. Thus, the protein would have a topology that, in mammalian cells, is shared only by a minor, but pathologically important, topological isoform of the prion protein (PrP). The human orthologue of this protein has been described previously (BST-2 or HM1.24 antigen) as a cell surface molecule that appears to be involved in early pre-B-cell development and which is present at elevated levels at the surface of myeloma cells. We show that rat BST-2/HM1.24 has both a cell surface and an intracellular (juxtanuclear) location and is efficiently internalized from the cell surface. We also show that the cell surface pool of BST-2/HM1.24 is predominantly present in the apical plasma membrane of polarized cells. The fact that rat BST-2/HM1.24 apparently possesses a GPI anchor led us to speculate that it might exist in cholesterol-rich lipid microdomains (lipid rafts) at the plasma membrane. Data from several experiments are consistent with this localization. We present a model in which BST-2/HM1.24 serves to link adjacent lipid rafts within the plasma membrane.
Publication
Journal: Kidney International
February/25/2004
Abstract
Conventional risk factors of cardiovascular disease and mortality in the general population such as body mass, serum cholesterol, and blood pressure are also found to relate to outcome in maintenance dialysis patients, but often in an opposite direction. Obesity, hypercholesterolemia, and hypertension appear to be protective features that are associated with a greater survival among dialysis patients. A similar protective role has been described for high serum creatinine and possibly homocysteine levels in end-stage renal disease (ESRD) patients. These findings are in contrast to the well-known association between over-nutrition and poor outcome in the general population. The association between under-nutrition and adverse cardiovascular outcome in dialysis patients, which stands in contrast to that seen in non-ESRD individuals, has been referred to as "reverse epidemiology." Publication bias may have handicapped or delayed additional reports with such paradoxical findings in ESRD patients. The etiology of this inverse association between conventional risk factors and clinical outcome in dialysis patients is not clear. Several possible causes are hypothesized. First, survival bias may play a role since only a small number of patients with chronic kidney disease (CKD) survive long enough to reach ESRD. Hence, the dialysis patients are probably a distinctively selected population out of CKD patients and may not represent the risk factor constellations of their CKD predecessors. Second, the time discrepancy between competitive risk factors may play a role. For example, the survival disadvantages of under-nutrition, which is frequently present in dialysis patients, may have a major impact on mortality in a shorter period of time, and this overwhelms the long-term negative effects of over-nutrition on survival. Third, the presence of the "malnutrition-inflammation complex syndrome" (MICS) in dialysis patients may also explain the existence of reverse epidemiology in dialysis patients. Both protein-energy malnutrition and inflammation or the combination of the two are much more common in dialysis patients than in the general population and many elements of MICS, such as low weight-for-height, hypocholesterolemia, or hypocreatininemia, are known risk factors of poor outcome in dialysis patients. The existence of reverse epidemiology may have a bearing on the management of dialysis patients. It is possible that new standards or goals for such traditional risk factors as body mass, serum cholesterol, and blood pressure should be considered for these individuals.
Publication
Journal: Proceedings of the National Academy of Sciences of the United States of America
May/20/2001
Abstract
The peroxisome proliferator-activated receptors (PPARs) are dietary lipid sensors that regulate fatty acid and carbohydrate metabolism. The hypolipidemic effects of the fibrate drugs and the antidiabetic effects of the glitazone drugs in humans are due to activation of the alpha (NR1C1) and gamma (NR1C3) subtypes, respectively. By contrast, the therapeutic potential of the delta (NR1C2) subtype is unknown, due in part to the lack of selective ligands. We have used combinatorial chemistry and structure-based drug design to develop a potent and subtype-selective PPARdelta agonist, GW501516. In macrophages, fibroblasts, and intestinal cells, GW501516 increases expression of the reverse cholesterol transporter ATP-binding cassette A1 and induces apolipoprotein A1-specific cholesterol efflux. When dosed to insulin-resistant middle-aged obese rhesus monkeys, GW501516 causes a dramatic dose-dependent rise in serum high density lipoprotein cholesterol while lowering the levels of small-dense low density lipoprotein, fasting triglycerides, and fasting insulin. Our results suggest that PPARdelta agonists may be effective drugs to increase reverse cholesterol transport and decrease cardiovascular disease associated with the metabolic syndrome X.
Publication
Journal: Annals of Internal Medicine
February/18/1998
Abstract
BACKGROUND
Carotid arterial intima-media thickness is used as a noninvasive surrogate end point to measure progression of atherosclerosis, but its relation to coronary events has not been fully explored.
OBJECTIVE
To determine whether carotid arterial intima-media thickness predicts coronary events.
METHODS
Long-term follow-up (average, 8.8 years) of a previously assembled cohort of persons who completed the 2-year Cholesterol Lowering Atherosclerosis Study, a randomized arterial imaging trial designed to study the effects of lipid lowering on progression of atherosclerosis.
METHODS
University-based ultrasonography laboratory.
METHODS
146 men 40 to 59 years of age who had previously had coronary artery bypass graft surgery.
METHODS
Preintrusive atherosclerosis in the common carotid artery was evaluated every 6 months with B-mode ultrasonography, and intrusive atherosclerosis in the coronary arteries was evaluated at baseline and at 2 years with quantitative coronary angiography. After the trial, the incidences of coronary events (nonfatal acute myocardial infarction, coronary death, and coronary artery revascularization) were documented.
RESULTS
For each 0.03-mm increase per year in carotid arterial intima-media thickness, the relative risk for nonfatal myocardial infarction or coronary death was 2.2 (95% CI, 1.4 to 3.6) and the relative risk for any coronary event was 3.1 (CI, 2.1 to 4.5) (P < 0.001). Absolute intima-media thickness was also related to risk for clinical coronary events (P < 0.02). Absolute thickness and progression in thickness predicted risk for coronary events beyond that predicted by coronary arterial measures of atherosclerosis and lipid measurements (P < 0.001).
CONCLUSIONS
Noninvasive B-mode ultrasonographic measurement of progression of intima-media thickness in the distal common carotid artery is a useful surrogate end point for clinical coronary events.
Publication
Journal: Arthritis and rheumatism
December/3/2008
Abstract
OBJECTIVE
To examine the efficacy and safety of the humanized anti-interleukin-6 receptor antibody tocilizumab combined with conventional disease-modifying antirheumatic drugs (DMARDs) in patients with active rheumatoid arthritis (RA).
METHODS
A total of 1,220 patients were randomized (2:1 ratio) in the phase III, double-blind, placebo-controlled, multicenter TOWARD (Tocilizumab in Combination With Traditional DMARD Therapy) study. Patients remained on stable doses of DMARDs and received tocilizumab 8 mg/kg or placebo (control group) every 4 weeks for 24 weeks.
RESULTS
At week 24, the proportion of patients achieving a response according to the American College of Rheumatology criteria for 20% improvement (ACR20) was significantly greater in the tocilizumab plus DMARD group than in the control group (61% versus 25%; P<0.0001). Secondary end points including 50% or 70% improvement (ACR50/70), the Disease Activity Score in 28 joints (DAS28), DAS28 remission responses (DAS28<2.6), European League Against Rheumatism responses, and systemic markers such as the C-reactive protein and hemoglobin levels showed superiority of tocilizumab plus DMARDs over DMARDs alone. Seventy-three percent of patients in the tocilizumab group had>>or=1 adverse event (AE), compared with 61% of patients in the control group. AEs leading to withdrawal from the study were infrequent (4% of patients in the tocilizumab group and 2% of those in the control group). Serious AEs occurred in 6.7% and 4.3% of patients in the tocilizumab and control groups, respectively, and serious infections occurred in 2.7% and 1.9%, respectively. Elevations in the alanine aminotransferase level, from normal at baseline to >3-fold the upper limit of normal, occurred in 4% of patients in the tocilizumab group and 1% of those in the control group, and elevated total cholesterol levels were observed in 23% and 6% of patients, respectively. Sixteen patients started lipid-lowering therapy during the study. Grade 3 neutropenia occurred in 3.7% of patients receiving tocilizumab and none of the patients in the control group, and no grade 4 neutropenia was reported.
CONCLUSIONS
Tocilizumab combined with any of the DMARDs evaluated was safe and effective in reducing articular and systemic symptoms in patients with an inadequate response to these agents.
Publication
Journal: New England Journal of Medicine
May/20/2008
Abstract
BACKGROUND
The incremental usefulness of adding multiple biomarkers from different disease pathways for predicting the risk of death from cardiovascular causes has not, to our knowledge, been evaluated among the elderly.
METHODS
We used data from the Uppsala Longitudinal Study of Adult Men (ULSAM), a community-based cohort of elderly men, to investigate whether a combination of biomarkers that reflect myocardial cell damage, left ventricular dysfunction, renal failure, and inflammation (troponin I, N-terminal pro-brain natriuretic peptide, cystatin C, and C-reactive protein, respectively) improved the risk stratification of a person beyond an assessment that was based on the established risk factors for cardiovascular disease (age, systolic blood pressure, use or nonuse of antihypertensive treatment, total cholesterol, high-density lipoprotein cholesterol, use or nonuse of lipid-lowering treatment, presence or absence of diabetes, smoking status, and body-mass index).
RESULTS
During follow-up (median, 10.0 years), 315 of the 1135 participants in our study (mean age, 71 years at baseline) died; 136 deaths were the result of cardiovascular disease. In Cox proportional-hazards models adjusted for established risk factors, all of the biomarkers significantly predicted the risk of death from cardiovascular causes. The C statistic increased significantly when the four biomarkers were incorporated into a model with established risk factors, both in the whole cohort (C statistic with biomarkers vs. without biomarkers, 0.766 vs. 0.664; P<0.001) and in the group of 661 participants who did not have cardiovascular disease at baseline (0.748 vs. 0.688, P=0.03). The improvement in risk assessment remained strong when it was estimated by other statistical measures of model discrimination, calibration, and global fit.
CONCLUSIONS
Our data suggest that in elderly men with or without prevalent cardiovascular disease, the simultaneous addition of several biomarkers of cardiovascular and renal abnormalities substantially improves the risk stratification for death from cardiovascular causes beyond that of a model that is based only on established risk factors.
Publication
Journal: The Lancet
January/9/2002
Abstract
BACKGROUND
Apolipoprotein B (apoB) and apolipoprotein A-I (apoA-I) are thought to be better predictors of acute myocardial infarction than total cholesterol and LDL-cholesterol. We investigated whether apoB and apoA-I are predictors of risk of fatal myocardial infarction. We also aimed to establish whether apoB and apoA-I add further information about risk of fatal myocardial infarction to that obtained with total cholesterol, triglycerides, and LDL-cholesterol.
METHODS
We recruited 175553 individuals mainly from screening programmes. We measured concentrations of apoB, apoA-I, total cholesterol, and triglycerides, and calculated apoB/apoA-I ratio and concentrations of LDL-cholesterol and HDL-cholesterol. The relation between death from acute myocardial infarction and initial values for apoB, apoA-I, and the other lipids was examined.
RESULTS
Mean follow-up was 66.8 months (SD 41.3) for 98722 men and 64.4 months (41.4) for 76831 women. 864 men and 359 women had fatal myocardial infarction. In univariate analyses adjusted for age and in multivariate analyses adjusted for age, total cholesterol, and triglycerides, the values for apoB and apoB/apoA-I ratio were strongly and positively related to increased risk of fatal myocardial infarction in men and in women. ApoA-I was noted to be protective. In multivariate analysis, apoB was a stronger predictor of risk than LDL-cholesterol in both sexes.
CONCLUSIONS
Although LDL-cholesterol and HDL-cholesterol are known risk factors, we suggest that apoB, apoB/apoA-I, and apoA-I should also be regarded as highly predictive in evaluation of cardiac risk. Although increased throughout the range of values of LDL-cholesterol, apoB and apoA-I might be of greatest value in diagnosis and treatment in men and women who have common lipid abnormalities, but have normal or low concentrations of LDL-cholesterol.
Publication
Journal: Proceedings of the National Academy of Sciences of the United States of America
May/26/2010
Abstract
We executed a genome-wide association scan for age-related macular degeneration (AMD) in 2,157 cases and 1,150 controls. Our results validate AMD susceptibility loci near CFH (P < 10(-75)), ARMS2 (P < 10(-59)), C2/CFB (P < 10(-20)), C3 (P < 10(-9)), and CFI (P < 10(-6)). We compared our top findings with the Tufts/Massachusetts General Hospital genome-wide association study of advanced AMD (821 cases, 1,709 controls) and genotyped 30 promising markers in additional individuals (up to 7,749 cases and 4,625 controls). With these data, we identified a susceptibility locus near TIMP3 (overall P = 1.1 x 10(-11)), a metalloproteinase involved in degradation of the extracellular matrix and previously implicated in early-onset maculopathy. In addition, our data revealed strong association signals with alleles at two loci (LIPC, P = 1.3 x 10(-7); CETP, P = 7.4 x 10(-7)) that were previously associated with high-density lipoprotein cholesterol (HDL-c) levels in blood. Consistent with the hypothesis that HDL metabolism is associated with AMD pathogenesis, we also observed association with AMD of HDL-c-associated alleles near LPL (P = 3.0 x 10(-3)) and ABCA1 (P = 5.6 x 10(-4)). Multilocus analysis including all susceptibility loci showed that 329 of 331 individuals (99%) with the highest-risk genotypes were cases, and 85% of these had advanced AMD. Our studies extend the catalog of AMD associated loci, help identify individuals at high risk of disease, and provide clues about underlying cellular pathways that should eventually lead to new therapies.
Publication
Journal: Science
January/3/2001
Abstract
Niemann-Pick type C2 disease (NP-C2) is a fatal hereditary disorder of unknown etiology characterized by defective egress of cholesterol from lysosomes. Here we show that the disease is caused by a deficiency in HE1, a ubiquitously expressed lysosomal protein identified previously as a cholesterol-binding protein. HE1 was undetectable in fibroblasts from NP-C2 patients but present in fibroblasts from unaffected controls and NP-C1 patients. Mutations in the HE1 gene, which maps to chromosome 14q24.3, were found in NP-C2 patients but not in controls. Treatment of NP-C2 fibroblasts with exogenous recombinant HE1 protein ameliorated lysosomal accumulation of low density lipoprotein-derived cholesterol.
Publication
Journal: Science
July/29/2012
Abstract
Pharmacological responses of G protein-coupled receptors (GPCRs) can be fine-tuned by allosteric modulators. Structural studies of such effects have been limited due to the medium resolution of GPCR structures. We reengineered the human A(2A) adenosine receptor by replacing its third intracellular loop with apocytochrome b(562)RIL and solved the structure at 1.8 angstrom resolution. The high-resolution structure allowed us to identify 57 ordered water molecules inside the receptor comprising three major clusters. The central cluster harbors a putative sodium ion bound to the highly conserved aspartate residue Asp(2.50). Additionally, two cholesterols stabilize the conformation of helix VI, and one of 23 ordered lipids intercalates inside the ligand-binding pocket. These high-resolution details shed light on the potential role of structured water molecules, sodium ions, and lipids/cholesterol in GPCR stabilization and function.
Publication
Journal: New England Journal of Medicine
August/1/2013
Abstract
BACKGROUND
Alzheimer's disease is characterized by the presence of cortical amyloid-beta (Aβ) protein plaques, which result from the sequential action of β-secretase and γ-secretase on amyloid precursor protein. Semagacestat is a small-molecule γ-secretase inhibitor that was developed as a potential treatment for Alzheimer's disease.
METHODS
We conducted a double-blind, placebo-controlled trial in which 1537 patients with probable Alzheimer's disease underwent randomization to receive 100 mg of semagacestat, 140 mg of semagacestat, or placebo daily. Changes in cognition from baseline to week 76 were assessed with the use of the cognitive subscale of the Alzheimer's Disease Assessment Scale for cognition (ADAS-cog), on which scores range from 0 to 70 and higher scores indicate greater cognitive impairment, and changes in functioning were assessed with the Alzheimer's Disease Cooperative Study-Activities of Daily Living (ADCS-ADL) scale, on which scores range from 0 to 78 and higher scores indicate better functioning. A mixed-model repeated-measures analysis was used.
RESULTS
The trial was terminated before completion on the basis of a recommendation by the data and safety monitoring board. At termination, there were 189 patients in the group receiving placebo, 153 patients in the group receiving 100 mg of semagacestat, and 121 patients in the group receiving 140 mg of semagacestat. The ADAS-cog scores worsened in all three groups (mean change, 6.4 points in the placebo group, 7.5 points in the group receiving 100 mg of the study drug, and 7.8 points in the group receiving 140 mg; P=0.15 and P=0.07, respectively, for the comparison with placebo). The ADCS-ADL scores also worsened in all groups (mean change at week 76, -9.0 points in the placebo group, -10.5 points in the 100-mg group, and -12.6 points in the 140-mg group; P=0.14 and P<0.001, respectively, for the comparison with placebo). Patients treated with semagacestat lost more weight and had more skin cancers and infections, treatment discontinuations due to adverse events, and serious adverse events (P<0.001 for all comparisons with placebo). Laboratory abnormalities included reduced levels of lymphocytes, T cells, immunoglobulins, albumin, total protein, and uric acid and elevated levels of eosinophils, monocytes, and cholesterol; the urine pH was also elevated.
CONCLUSIONS
As compared with placebo, semagacestat did not improve cognitive status, and patients receiving the higher dose had significant worsening of functional ability. Semagacestat was associated with more adverse events, including skin cancers and infections. (Funded by Eli Lilly; ClinicalTrials.gov number, NCT00594568.)
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