Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 85
Filter
4.
Congenit Heart Dis ; 12(1): 74-83, 2017 Jan.
Article in English | MEDLINE | ID: mdl-27600478

ABSTRACT

BACKGROUND: Stent implantation is the treatment of choice for adolescents and adults with aortic coarctation (CoAo). Despite excellent short-term results, 20%-40% of the patients develop arterial hypertension later in life, which was attributed to inappropriate response of the aortic baroreceptors to increased stiffness of the ascending aorta (ASAO), either congenital or induced by CoAo repair. In particular, it has been hypothesized that stent itself may cause or sustain hypertension. Therefore, we aimed to study the hemodynamic and structural impact following stent implantation in the normal aorta of a growing animal. METHODS: Eight female sheep completed the study and a stent was implanted in four. Every 3 mo we measured blood pressure of the anterior and posterior limbs and left ventricular function by echocardiography. Twelve months later invasive pressure was measured under baseline and simulated stress conditions. Expression of genes indicating oxidative stress (OS), endothelial dysfunction (ED) and stiffness, as well as pathological examination were performed in ascending (ASAO) and descending aorta (DSAO). RESULTS: SOD1 and MMP9 gene expression were higher in ASAO of the stented animals, compared to DSAO and controls, while NOS3 was decreased. No differences were found in blood pressure and echocardiographic parameters. No histological differences were found in the aorta of the two groups of animals. CONCLUSIONS: Stent does not affect central and peripheral hemodynamics, cardiac structure and function even in the long term. However, the finding of markers of OS and increased stiffness of ASAO, proximal to the stent, points to molecular mechanisms for increased cardiovascular risk of patients with stented CoAo.


Subject(s)
Aorta, Thoracic/physiopathology , Blood Pressure , Endothelium, Vascular/physiopathology , Endovascular Procedures/adverse effects , Endovascular Procedures/instrumentation , Hypertension/etiology , Stents , Animals , Aorta, Thoracic/growth & development , Aorta, Thoracic/metabolism , Aorta, Thoracic/pathology , Echocardiography, Stress , Endothelium, Vascular/growth & development , Endothelium, Vascular/metabolism , Endothelium, Vascular/pathology , Female , Gene Expression Regulation, Enzymologic , Hypertension/genetics , Hypertension/metabolism , Hypertension/physiopathology , Matrix Metalloproteinase 9/genetics , Matrix Metalloproteinase 9/metabolism , Models, Animal , Nitric Oxide Synthase Type III/genetics , Nitric Oxide Synthase Type III/metabolism , Oxidative Stress , Risk Factors , Sheep, Domestic , Superoxide Dismutase-1/genetics , Superoxide Dismutase-1/metabolism , Time Factors , Vascular Stiffness , Ventricular Function, Left
6.
High Blood Press Cardiovasc Prev ; 22(3): 225-32, 2015 Sep.
Article in English | MEDLINE | ID: mdl-25903425

ABSTRACT

Hypertension is a common disorder of multifactorial origin that constitutes a major risk factor for cardiovascular events such as stroke and myocardial infarction. The subunits of the heterotrimeric G proteins are attractive candidate gene products for susceptibility to hypertension, obesity and insulin resistance syndrome. A polymorphism (825C/T) in exon 10 of the GNB3 gene, encoding for the Gß3 subunit, has been described. The 825T allele is associated with alternative splicing of the gene and formation of a truncated but functionally active ß3 subunit. Many studies have investigated whether carriers of the 825T allele are at increased risk for hypertension, obesity, insulin-resistance and left ventricular hypertrophy with apparently conflicting results. The present review demonstrates that GNB3 825T allele is a useful genetic marker for better defining the risk profile of hypertensive patients, as it is associated with increased risk of stroke and myocardial infarction in longitudinal studies in Caucasians.


Subject(s)
Coronary Artery Disease/genetics , Heterotrimeric GTP-Binding Proteins/genetics , Hypertension/genetics , Hypertrophy, Left Ventricular/genetics , Obesity/genetics , Stroke/genetics , Alleles , Coronary Artery Disease/ethnology , Essential Hypertension , Humans , Metabolic Syndrome/genetics , Polymorphism, Single Nucleotide , Stroke/ethnology
7.
Vascul Pharmacol ; 70: 35-44, 2015 Jul.
Article in English | MEDLINE | ID: mdl-25863291

ABSTRACT

Ischemia-reperfusion (IR) leads to severe organ injury and dysfunction. Sirtuins (SIRTs) are a family of histone deacetylases (HDACs) that require nicotinamide adenine dinucleotide (NAD(+)) for the deacetylation reaction. SIRTs play a major role in counteracting cellular stress and apoptosis. This study aimed to investigate the mechanisms of heart protection against apoptosis by SIRTs and the molecular pathways involved in SIRTs regulation and function in a rat model of IR injury. Hearts of male Wistar-Kyoto rats were subjected to 30-min ischemia followed by reperfusion up to 6h. IR increased cardiomyocyte apoptosis; the cleavage of caspase 3, induced a transient upregulation of SIRT1 and downregulation of SIRT6 expression, but decreased SIRT1 activity and reduced NAD(+) content. IR also increased forkhead box protein O1 (FoxO1) expression and FoxO1 binding to SIRT1 promoter region. Resveratrol restored SIRT1 activity and NAD(+) level by an AMPK-dependent mechanism, reduced cardiomyocyte apoptosis, and attenuated caspase 3 cleavage via heat shock factor-1 deacetylation and heat shock protein (HSP) expression upregulation. Our data show new potential molecular mechanisms of up and downstream regulation of SIRT1 in IR. The interplay among FoxO1, SIRT1, NAD(+), AMPK, HSP, and SIRT6 depicts a complex molecular network that protects the heart from apoptosis during IR and may be susceptible to therapeutic interventions.


Subject(s)
Apoptosis , Myocardial Reperfusion Injury/prevention & control , Myocytes, Cardiac/enzymology , NAD/metabolism , Sirtuin 1/metabolism , AMP-Activated Protein Kinases/metabolism , Animals , Apoptosis/drug effects , Binding Sites , Caspase 3/metabolism , DNA-Binding Proteins/metabolism , Enzyme Activation , Forkhead Transcription Factors/metabolism , Glucose/deficiency , Heat Shock Transcription Factors , Isolated Heart Preparation , Male , Myocardial Reperfusion Injury/enzymology , Myocardial Reperfusion Injury/genetics , Myocardial Reperfusion Injury/pathology , Myocytes, Cardiac/drug effects , Myocytes, Cardiac/pathology , Nerve Tissue Proteins/metabolism , Promoter Regions, Genetic , Rats, Inbred WKY , Resveratrol , Signal Transduction , Sirtuin 1/genetics , Sirtuins/metabolism , Stilbenes/pharmacology , Time Factors , Transcription Factors/metabolism
8.
J Cardiovasc Med (Hagerstown) ; 16(5): 372-82, 2015 May.
Article in English | MEDLINE | ID: mdl-25575271

ABSTRACT

Severe acute arterial hypertension is usually defined as 'hypertensive crisis', although 'hypertensive emergencies' or 'hypertensive urgencies', as suggested by the Joint National Committee and the European Society of Hypertension, have completely different diagnostic and therapeutic approaches.The prevalence and demographics of hypertensive emergencies and urgencies have changed over the last four decades, but hypertensive emergencies and urgencies are still associated with significant morbidity and mortality.Different scientific societies have repeatedly produced up-to-date guidelines; however, the treatment of hypertensive emergencies and urgencies is still inappropriate, with potential clinical implications.This review focuses on hypertensive emergencies and urgencies management and treatment, as suggested by recent data.


Subject(s)
Hypertension/diagnosis , Hypertension/therapy , Acute Disease , Aortic Dissection/etiology , Aortic Aneurysm/etiology , Disease Management , Emergencies , Heart Failure/etiology , Humans , Hypertension/epidemiology , Hypertension/etiology , Stroke/etiology , Terminology as Topic
9.
Pharmacogenomics ; 15(13): 1643-52, 2014 Sep.
Article in English | MEDLINE | ID: mdl-25410890

ABSTRACT

BACKGROUND: Essential hypertension arises from the combined effect of genetic and environmental factors. A pharmacogenomics approach could help to identify additional molecular mechanisms involved in its pathogenesis. AIM: The aim of SOPHIA study was to identify genetic polymorphisms regulating blood pressure response to the angiotensin II receptor blocker, losartan, with a whole-genome approach. MATERIALS & METHODS: We performed a genome-wide association study on blood pressure response in 372 hypertensives treated with losartan and we looked for replication in two independent samples. RESULTS: We identified a peak of association in CAMK1D gene (rs10752271, effect size -5.5 ± 0.94 mmHg, p = 1.2 × 10(-8)). CAMK1D encodes a protein that belongs to the regulatory pathway involved in aldosterone synthesis. We tested the specificity of rs10752271 for losartan in hypertensives treated with hydrochlorothiazide and we validated it in silico in the GENRES cohort. CONCLUSION: Using a genome-wide approach, we identified the CAMK1D gene as a novel locus associated with blood pressure response to losartan. CAMK1D gene characterization may represent a useful tool to personalize the treatment of essential hypertension.


Subject(s)
Angiotensin II Type 1 Receptor Blockers/therapeutic use , Blood Pressure/drug effects , Calcium-Calmodulin-Dependent Protein Kinase Type 1/genetics , Genome-Wide Association Study , Hypertension/drug therapy , Losartan/therapeutic use , Polymorphism, Single Nucleotide , Adult , Female , Humans , Hydrochlorothiazide/therapeutic use , Hypertension/genetics , Hypertension/physiopathology , Losartan/pharmacology , Male , Middle Aged
10.
Clin Sci (Lond) ; 127(7): 449-61, 2014 Oct.
Article in English | MEDLINE | ID: mdl-24702436

ABSTRACT

Chronic inflammation and hyperglycaemia, typical features of metabolic diseases, trigger endothelial damage and release of E-selectin, a marker of endothelial activation. In the present study, we investigated molecular pathways involved in the regulation of endothelial cell activation induced by tumour necrosis factor-α (TNF-α) and high glucose. In cultured human umbilical vein endothelial cells (HUVECs), we studied the role of HuR, an ELAV (embryonic lethal, abnormal vision, Drosophila) family RNA-binding protein, and Sirtuin 1 (SIRT1) on E-selectin release and cell adhesion at different glucose concentrations. HuR expression and binding to SIRT1 were also analysed ex vivo in peripheral blood mononuclear cells (PBMCs) of subjects with and without the metabolic syndrome (MS), by immunoprecipitation (IP) of the ribonucleoprotein (RNP) complex. We found that SIRT1 overexpression prevented TNF-α- and high-glucose-dependent nuclear factor-κB (NF-κB)-p65 acetylation, E-selectin promoter activity, E-selectin release and adhesion of THP-1 cells to HUVECs. The same was mimicked by HuR overexpression, which binds and stabilizes SIRT1 mRNA. Importantly, in PBMCs of individuals with MS compared with those without, SIRT1 expression was lower, and the ability of HuR to bind SIRT1 mRNA was significantly reduced, while plasma E-selectin was increased. We conclude that post-transcriptional stabilization of SIRT1 by HuR represses inflammation- and hyperglycaemia-induced E-selectin release and endothelial cell activation. Therefore, increasing SIRT1 expression represents a strategy to counter the accelerated vascular disease in metabolic disorders.


Subject(s)
E-Selectin/physiology , ELAV Proteins/physiology , Endothelial Cells/metabolism , Metabolic Syndrome/metabolism , Sirtuin 1/physiology , Tumor Necrosis Factor-alpha/metabolism , Acetylation , Adhesiveness , Benzamides/pharmacology , Cell Adhesion , E-Selectin/metabolism , Endothelial Cells/cytology , Endothelial Cells/physiology , Gene Expression Regulation/drug effects , Glucose/metabolism , Human Umbilical Vein Endothelial Cells , Humans , Hyperglycemia/genetics , Hyperglycemia/metabolism , Leukocytes, Mononuclear/metabolism , Metabolic Syndrome/pathology , NF-kappa B/genetics , NF-kappa B/metabolism , Naphthols/pharmacology , Protein Stability , Resveratrol , Sirtuin 1/genetics , Sirtuin 1/metabolism , Stilbenes/pharmacology
11.
Am J Emerg Med ; 32(4): 334-41, 2014 Apr.
Article in English | MEDLINE | ID: mdl-24559907

ABSTRACT

INTRODUCTION: Mid-regional pro-atrial natriuretic peptide (MR-proANP), procalcitonin (PCT), and mid-regional pro-adrenomedullin (MR-proADM) demonstrated usefulness for management of emergency department patients with dyspnea. METHODS: To evaluate in patients with dyspnea, the prognostic value for 30 and 90 days mortality and readmission of PCT, MR-proADM, and MR-proANP, a multicenter prospective study was performed evaluating biomarkers at admission, 24 and 72 hours after admission. Based on final diagnosis, patients were divided into acute heart failure (AHF), primary lung diseases, or both (AHF + NO AHF). RESULTS: Five hundred one patients were enrolled. Procalcitonin and MR-proADM values at admission and at 72 hours were significantly (P < .001) predictive for 30-day mortality: baseline PCT with an area under the curve (AUC) of 0.70 and PCT at 72 hours with an AUC of 0.61; baseline MR-proADM with an AUC of 0.62 and MR-proADM at 72 hours with an AUC of 0.68. As for 90-day mortality, both PCT and MR-proADM baseline and 72 hours values showed a significant (P < .0001) predictive ability: baseline PCT with an AUC of 0.73 and 72 hours PCT with an AUC of 0.64; baseline MR-proADM with an AUC of 0.66 and 72 hours MR-proADM with an AUC of 0.71. In AHF, group biomarkers predicted rehospitalization and mortality at 90 days, whereas in AHF + NO AHF group, they predict mortality at 30 and 90 days. CONCLUSIONS: In patients admitted for dyspnea, assessment of PCT plus MR-proADM improves risk stratification and management. Combined use of biomarkers is able to predict in the total cohort both rehospitalization and death at 30 and 90 days.


Subject(s)
Adrenomedullin/blood , Calcitonin/blood , Dyspnea/blood , Dyspnea/mortality , Heart Failure/blood , Heart Failure/mortality , Lung Diseases/blood , Lung Diseases/mortality , Protein Precursors/blood , Aged , Aged, 80 and over , Biomarkers/blood , Calcitonin Gene-Related Peptide , Emergency Service, Hospital , Female , Hospital Mortality , Humans , Italy/epidemiology , Male , Patient Admission/statistics & numerical data , Predictive Value of Tests , Prognosis , Prospective Studies , Risk Assessment
13.
Ann Plast Surg ; 71(1): 6-9, 2013 Jul.
Article in English | MEDLINE | ID: mdl-23241761

ABSTRACT

Nowadays, an urgent need for global medical cooperation and assistance still bears on health care providers. Because plastic, reconstructive, and aesthetic surgery is a surgical specialty with social purposes, the humanitarian importance of the discipline is, nowadays, stronger than ever. Padova Hospitale Onlus is a nonprofit charity association with the aim to ensure sustainable medical programs, in particular in the field of plastic and reconstructive surgery. The activity of the association in fund-raising strategies, volunteer enrollment, and operative strategies has been reviewed and reported to stimulate further collaboration, emulation, and contributions. Since 1996, the association has assisted over 20,000 people during 50 missions over the 5 continents, performing more than 2000 surgical operations and almost 8000 medical examination, involving more than 320 volunteers, supplying health care material or health care facilities. Furthermore, a high rate of surgical records and of medical assistance has been performed in the last 2 years, depicting a positive rising trend of activity. However, scarce financial means, absence of a structured coordination, and/or cooperation between associations may often affect the long-term sustainability of these interventions. Thus, only an experienced and structured association may grant the required resources to sustain adequate and fruitful short-term or long-term projects for the promotion of a humanitarian cooperation as much "demand driven" as possible.


Subject(s)
Charities , Developing Countries , Medical Missions , Plastic Surgery Procedures , Volunteers , Altruism , Fund Raising , Hospitals , Humans , Italy , Plastic Surgery Procedures/statistics & numerical data
14.
Arch Gerontol Geriatr ; 52(3): e185-91, 2011.
Article in English | MEDLINE | ID: mdl-21145118

ABSTRACT

The goal of this study was to examine the relationship between BP variations and neurological deficit outcome in old-old patients after AIS. Fifty-four patients (66-96 years), admitted consecutively for stroke were assessed, using a non-invasive BP monitoring (NIBPM), measuring mean systolic (SBP) and diastolic (DBP) blood pressure and their variation between days 1 and 7. Neurological assessment and cognitive function were evaluated using the NIH stroke Scale (NIHSS) and the short portable mental status Questionnaire (SPMSQ), respectively. Functional status was assessed using the modified Rankin scale (RS) and the Barthel index (BI). NIHSS on the 1st day positively correlated with SPMSQ score and with BI on day 21. The NIHSS variation (ΔNIHSS) between days 21 and 1 negatively correlated with mean 24-h BP change between days 7 and 1 (r=-0.59 for DBP and r=-0.54 for SBP; p<0.001). Age, severity of stroke at admission, history of hypertension, atrial fibrillation (AF) and BP levels at admission were not correlated to ΔNIHSS. An inverse correlation between the decrease of 24-h BP within the first week and ΔNIHSS suggests prudence in lowering BP in the acute phase of stroke in elderly.


Subject(s)
Aging , Blood Pressure/physiology , Brain Ischemia/physiopathology , Stroke/physiopathology , Age Factors , Aged , Aged, 80 and over , Cohort Studies , Female , Humans , Male , Neurologic Examination , Severity of Illness Index , Surveys and Questionnaires , Treatment Outcome
15.
Am J Hypertens ; 24(2): 241-6, 2011 Feb.
Article in English | MEDLINE | ID: mdl-20966899

ABSTRACT

BACKGROUND: A silent polymorphism (+1166 A/C single-nucleotide polymorphism) localized in the 3'-UTR (untranslated region) of the human angiotensin II type-1 receptor (AT1R) has been associated with hypertension and cardiovascular complications. The +1166 A/C is recognized by a specific microRNA-155 (miR-155), which is base-pairing complementary with the +1166 A-allele but not with the mutant +1166 C allele. Aim of our study was to investigate the interplay between miR-155 and AT1R protein expression. METHODS: Sixty-four subjects were selected for the +1166 A/C from the cohort of hypertensives (n = 573) of the Hypertension and Ambulatory Recording Venetia Study (HARVEST): 25 were homozygous for the 1166 A allele, 20 heterozygous, and 19 homozygous for the 1166 C allele. RESULTS: miR-155 expression was significantly decreased in subjects with CC genotype in comparison to AA and AC genotype. AT1R protein expression was significantly increased in the CC group in comparison to AA and AC (P < 0.01) although AT1R mRNA expression was not significantly different in the three groups. AT1R protein expression was positively correlated with systolic and diastolic blood pressure and negatively correlated with miR-155 expression level. Plasma transforming growth factor-ß1 (TGF-ß1) may have a modulator role in the interplay between miR-155 and AT1R protein expression as it was correlated negatively with miR-155 expression and positively with AT1R protein expression in subjects with CC genotype. CONCLUSION: The interplay between miR-155 expression, +1166C polymorphism, and AT1R protein expression may have a role in the regulation of blood pressure.


Subject(s)
Blood Pressure/genetics , Hypertension/genetics , MicroRNAs/analysis , Polymorphism, Genetic , Receptor, Angiotensin, Type 1/genetics , 3' Untranslated Regions , Adult , Age of Onset , Female , Genetic Predisposition to Disease , Heterozygote , Homozygote , Humans , Hypertension/blood , Hypertension/epidemiology , Hypertension/physiopathology , Italy/epidemiology , Male , Phenotype , Prospective Studies , RNA, Messenger/blood , Receptor, Angiotensin, Type 1/blood , Transforming Growth Factor beta1/blood
16.
Crit Care ; 14(3): R116, 2010.
Article in English | MEDLINE | ID: mdl-20550660

ABSTRACT

INTRODUCTION: Our aim was to evaluate the role of B-type natriuretic peptide (BNP) percentage variations at 24 hours and at discharge compared to its value at admission in order to demonstrate its predictive value for outcomes in patients with acute decompensated heart failure (ADHF). METHODS: This was a multicenter Italian (8 centers) observational study (Italian Research Emergency Department: RED). 287 patients with ADHF were studied through physical exams, lab tests, chest X Ray, electrocardiograms (ECGs) and BNP measurements, performed at admission, at 24 hours, and at discharge. Follow up was performed 180 days after hospital discharge. Logistic regression analysis was used to estimate odds ratios (OR) for the various subgroups created. For all comparisons, a P value < 0.05 was considered statistically significant. RESULTS: BNP median (interquartile range (IQR)) value at admission was 822 (412 - 1390) pg\mL; at 24 hours was 593 (270 - 1953) and at discharge was 325 (160 - 725). A BNP reduction of >46% at discharge had an area under curve (AUC) of 0.70 (P < 0.001) for predicting future adverse events. There were 78 events through follow up and in 58 of these patients the BNP level at discharge was >300 pg/mL. A BNP reduction of 25.9% after 24 hours had an AUC at ROC curve of 0.64 for predicting adverse events (P < 0.001). The odds ratio of the patients whose BNP level at discharge was <300 pg/mL and whose percentage decrease at discharge was <46% compared to the group whose BNP level at discharge was <300 pg/mL and whose percentage decrease at discharge was >46% was 4.775 (95% confidence interval (CI) 1.76 - 12.83, P < 0.002). The odds ratio of the patients whose BNP level at discharge was >300 pg/mL and whose percentage decrease at discharge was <46% compared to the group whose BNP level at discharge was <300 pg/mL and whose percentage decrease at discharge was >46% was 9.614 (CI 4.51 - 20.47, P < 0.001). CONCLUSIONS: A reduction of BNP >46% at hospital discharge compared to the admission levels coupled with a BNP absolute value < 300 pg/mL seems to be a very powerful negative prognostic value for future cardiovascular outcomes in patients hospitalized with ADHF.


Subject(s)
Heart Failure/blood , Inpatients , Natriuretic Peptide, Brain/blood , Acute Disease , Aged , Aged, 80 and over , Female , Heart Failure/complications , Heart Failure/physiopathology , Humans , Italy , Male , Middle Aged , Odds Ratio , Predictive Value of Tests , Prognosis
17.
J Hypertens ; 28(5): 1104-8, 2010 May.
Article in English | MEDLINE | ID: mdl-20375904

ABSTRACT

OBJECTIVE: RGS2 (regulators of G-protein signalling) is a negative regulator of Galphaq protein signalling, which mediates the action of several vasoconstrictors. Low RGS2 expression increases G-protein-coupled signalling in hypertensive patients. The aim of the present study was to correlate RGS2 expression in peripheral blood mononuclear cells (PBMs) with response to antihypertensive therapy in never-treated patients with essential hypertension. METHODS AND DESIGN: RGS2 expression was measured by real-time quantitative RT-PCR in peripheral blood mononuclear cells (PBMs) from 102 essential hypertensives. The diagnosis of essential hypertension was based on all clinically required tests, including the captopril suppression test. Antihypertensive treatment was given in accordance to international guidelines. End-point of the study was systolic blood pressure (BP) less than 140 mmHg and diastolic BP less than 90 mmHg with three or less different antihypertensive agents, which identified responders to treatment. Resistant hypertension was defined as the failure to control systolic and/or diastolic BP despite at least three different classes of antihypertensive agents, including a diuretic. RESULTS: During follow-up, 85 (83%) patients reached the end point (responders). Resistant hypertensives (n = 17, 17%) were older, had higher baseline BP, plasma aldosterone and aldosterone: renin ratio (ARR) and lower plasma renin activity than patients who reached the end point. RGS2 was negatively correlated to systolic BP at enrollment and significantly lower in PBMs from resistant hypertensives in comparison with patients that reached BP goal. According to logistic regression analysis, high RGS2 expression was predictor of reaching BP goal, whereas high ARR after captopril, age and systolic pressure at enrolment were predictor of resistant hypertension. CONCLUSION: RGS2 expression affects the response to antihypertensive treatment. Reduced RGS2 expression contributes to resistance to antihypertensive agents through poor negative feedback on the effects of aldosterone and of other vasoactive agents.


Subject(s)
Aldosterone/blood , Antihypertensive Agents/therapeutic use , Hypertension/drug therapy , RGS Proteins/genetics , Renin/blood , Adolescent , Adult , Aged , Blood Pressure/drug effects , Cohort Studies , Drug Resistance , Feedback, Physiological , Female , Gene Expression/drug effects , Humans , Hypertension/blood , Hypertension/genetics , Hypertension/physiopathology , Male , Middle Aged , RNA, Messenger/blood , RNA, Messenger/genetics , Young Adult
18.
Diabetes ; 59(4): 1006-15, 2010 Apr.
Article in English | MEDLINE | ID: mdl-20068143

ABSTRACT

OBJECTIVE: Sirtuins (SIRTs) are NAD(+)-dependent deacetylases that regulate metabolism and life span. We used peripheral blood mononuclear cells (PBMCs) to determine ex vivo whether insulin resistance/metabolic syndrome influences SIRTs. We also assessed the potential mechanisms linking metabolic alterations to SIRTs in human monocytes (THP-1) in vitro. RESEARCH DESIGN AND METHODS: SIRT1-SIRT7 gene and protein expression was determined in PBMCs of 54 subjects (41 with normal glucose tolerance and 13 with metabolic syndrome). Insulin sensitivity was assessed by the minimal model analysis. Subclinical atherosclerosis was assessed by carotid intima-media thickness (IMT). In THP-1 cells exposed to high glucose or fatty acids in vitro, we explored SIRT1 expression, p53 acetylation, Jun NH(2)-terminal kinase (JNK) activation, NAD(+) levels, and nicotinamide phosphoribosyltransferase (NAMPT) expression. The effects of SIRT1 induction by resveratrol and of SIRT1 gene silencing were also assessed. RESULTS: In vivo, insulin resistance and metabolic syndrome were associated with low PBMC SIRT1 gene and protein expression. SIRT1 gene expression was negatively correlated with carotid IMT. In THP-1 cells, high glucose and palmitate reduced SIRT1 and NAMPT expression and reduced the levels of intracellular NAD(+) through oxidative stress. No effect was observed in cells exposed to linoleate or insulin. High glucose and palmitate increased p53 acetylation and JNK phosphorylation; these effects were abolished in siRNA SIRT1-treated cells. Glucose- and palmitate-mediated effects on NAMPT and SIRT1 were prevented by resveratrol in vitro. CONCLUSIONS: Insulin resistance and subclinical atherosclerosis are associated with SIRT1 downregulation in monocytes. Glucotoxicity and lypotoxicity play a relevant role in quenching SIRT1 expression.


Subject(s)
Down-Regulation , Insulin Resistance/genetics , Metabolic Syndrome/genetics , Sirtuin 1/genetics , Angiogenesis Inhibitors/pharmacology , Atherosclerosis/genetics , Atherosclerosis/pathology , Carotid Arteries/pathology , Glucose/pharmacology , Glucose Tolerance Test , Humans , Longevity , Metabolic Syndrome/pathology , Monocytes/physiology , Palmitic Acid/pharmacology , Reference Values , Resveratrol , Stilbenes/pharmacology , Tunica Intima/drug effects , Tunica Intima/pathology , Tunica Media/drug effects , Tunica Media/pathology
SELECTION OF CITATIONS
SEARCH DETAIL
...