Antonio Bonaiuto

Effects of aglycone genistein in a rat experimental model of postmenopausal metabolic syndrome

Genistein aglycone, a soy derived isoflavone, has been demonstrated to be effective in reducing cardiovascular risk in postmenopausal women. We therefore investigated its effects in an experimental model of postmenopausal metabolic syndrome. Female spontaneously hypertensive obese rats (SHROB, n=40), a genetic model of syndrome X, and age-matched Wistar Kyoto (WKY, n=40) rats were used. A group of SHROB (n=20) and WKY (n=20) animals were ovariectomized (OVX). Four weeks after surgery all animals were randomized to receive either genistein (54 mg/human equivalent dose/day for 4 weeks), or vehicle. Body weight, food intake, systolic blood pressure (SBP), heart rate, plasma glucose, insulin resistance (HOMA-IR), total plasma cholesterol and triglycerides, and uterine weights were studied. Furthermore, we investigated acetylcholine- and sodium nitroprusside-induced relaxation of aortic rings as well as NG-L-arginine (L-NMA: 10-100 mM) induced vasoconstriction in phenylephrine-precontracted aortic segments. Liver expression of the peroxisome proliferator-activated receptor alpha (PPARA and gamma (PPARG was also assessed. OVX animals had a slight increase in SBP, body weight, insulin resistance, and plasma cholesterol. OVX-SHROB rats showed also impaired endothelial responses, blunted L-NMA induced contraction (L-NMA 100 mM, WKY=2.2+/-0.3 g/mg tissue; OVX-SHROB=1.1+/-0.4 g/mg tissue). Genistein treatment decreased SBP and plasma lipids, ameliorated endothelial dysfunction and insulin resistance, increased HDL cholesterol, and enhanced liver expression of PPARA and PPARG. Our data suggest that genistein is effective in ameliorating cardiovascular profiles in an experimental model of postmenopausal metabolic syndrome, attenuating the features of this disease. The effects of genistein are likely mediated by PPARA and PPARG receptors. This evidence would support the rationale for some pilot clinical trials using genistein in postmenopausal women affected by metabolic syndrome.

Antioxidant effect of atorvastatin is independent of PON1 gene T(-107)C, Q192R and L55M polymorphisms in hypercholesterolaemic patients.

ABSTRACT Background: Serum paraoxonase (PON1), a high density lipoprotein (HDL)-bound antioxidant enzyme, plays a role in atherosclerosis. An increase in PON1 activity has been reported following statin treatment. Objective: In the present study the following factors were evaluated: the influence of PON1 gene Q192R, L55M and T(–107)C polymorphisms on the response of LDL oxidisability and PON1 activity to atorvastatin treatment. Research design and methods: 205 Sicilian subjects with primary hypercholesterolaemia (HCh) and 69 healthy subjects as controls were concurrently enrolled. Hypercholesterolaemic patients were randomly divided into two groups: an atorvastatin group (10 mg/day atorvastatin) and a placebo group. Lipid profile, markers of LDL resistance to in vitro oxidation (lag-phase, oxidation rate and thiobarbituric acid-reactive substances), vitamin E content in LDL, PON1 activity and genotypes in both HCh and control subjects were determined at baseline. The same parameters were measured again after 3 weeks of treatment in both the atorvastatin and placebo groups. Results: HCh subjects showed significantly lower LDL resistance to oxidation, vitamin E content and PON1 activity levels than controls. A strong association was found among PON1 T(–107)C genotypes, LDL susceptibility to oxidation, vitamin E content and PON1 activity. After treatment, the atorvastatin group displayed a significant decrease in total cholesterol, LDL-cholesterol levels, and LDL susceptibility to oxidation, and an increase in vitamin E content and PON1 activity, compared with baseline values. Unlike PON1 activity levels, no difference among PON1 gene polymorphisms and reduction in markers of LDL oxidisability was observed. Conclusions: These results show, for the first time, that atorvastatin is able to improve the resistance to LDL oxidation independently of PON1 gene polymorphism.

High mobility group box-1 expression correlates with poor outcome in lung injury patients

Chest trauma is frequently followed by pulmonary contusion and sepsis. High mobility group box-1 (HMGB-1) is a late mediator of severe sepsis that has been associated with mortality under experimental conditions. We studied HMGB-1 mRNA expression in patients with lung injury and its relationship with the severity of trauma and survival. A total of 24 consecutive patients with chest trauma referring to the Intensive Care Unit of Messina University Hospital, were enrolled. Lung trauma was established on the basis of chest X-ray and computed tomography. Injury Severity Score (ISS), Revised Trauma Score (RTS) and Glasgow Coma Scale (GCS) were also assessed. Accordingly to these results 6 patients were considered as controls because of no penetrating trauma and low ISS. Blood and broncho-alveolar lavage fluid (BALF) from chest trauma patients were withdrawn at admission and 24h after the beginning of the standard therapeutic protocol. HMGB-1 mRNA increased significantly in blood (r=0.84) and BALF (r=0.87) from patients with trauma and pulmonary contusion and positively correlated with the severity of trauma (based on ISS and RTS) and the final outcome. HMGB-1 protein levels were also elevated in BALF macrophages from severe trauma patients compared to control subjects, furthermore TNF-alpha and its receptor TNFR-1 mRNA levels were also markedly increased in patients with a poor outcome respect to other subjects. Our study suggests that HMGB-1 may be an early indicator of poor clinical outcome in patients with chest trauma.

Tissue Factor and Monocyte Chemoattractant Protein-1 Expression in Hypertensive Individuals with Normal or Increased Carotid Intima-Media Wall Thickness

BACKGROUND People with hypertension display an inflammatory pattern that includes increased plasma concentrations of monocyte chemoattractant protein 1 (MCP-1) and C-reactive protein (CRP) and enhanced expression of tissue factor (TF) mRNA in blood monocytes. METHODS In this study, we investigated the relationship between CRP concentrations and TF and MCP-1 mRNA expression in unstimulated and lipopolysaccharide (LPS)-stimulated monocytes isolated from hypertensives with or without an increase in carotid intima-media thickness (IMT). We also investigated the expression of TF and MCP-1 mRNA and MCP-1 protein after in vitro addition of CRP to monocytes. We measured CRP (by immunonephelometry) and monocyte expression of TF and MCP-1 (by real-time PCR) in 80 untreated hypertensive patients without clinical cardiovascular disease (CVD) or additional risk factors for CVD compared with 41 controls. Based on IMT measured by carotid Doppler ultrasonography, patients were classified into the categories of normal (< or =1 mm) or abnormal (>1 mm). TF and MCP-1 mRNA and MCP-1 protein (by Western blotting) were measured after in vitro addition of CRP to monocytes from 10 randomized controls as well as 10 hypertensives with IMT < or =1 mm and 10 with IMT >1 mm. RESULTS CRP and TF and MCP-1 mRNA concentrations were significantly higher in IMT >1 mm hypertensives vs those with IMT < or =1 mm and controls. CRP had no effect on monocyte TF mRNA from either hypertensives or controls. CRP-stimulated monocytes from hypertensives, however, showed increased MCP-1 mRNA and protein expression compared with controls and LPS-stimulated cells. CONCLUSIONS Our findings suggest that the inflammatory response of blood monocytes plays an important role in the development of atherosclerosis and hypertension.

Platelet activating factor-acetylhydrolase (PAF-AH) activity and HDL levels, but not PAF-AH gene polymorphisms, are associated with successful aging in Sicilian octogenarians

Background and aims: Aging is associated with an increased risk of developing atherosclerosis. Subjects over 80 years of age without cardiovascular disease provide a model to investigate the protective factors increasing their resistance to atherosclerotic disease. Platelet-activating factor acetylhydrolase (PAF-AH) is an enzyme associated with low density lipoprotein (LDL) and high density lipoprotein (HDL) inactivating platelet-activating factor (PAF) and preventing LDL oxidation by hydrolysis of oxidized phospholipids. The aim of the present study was to evaluate the contribution of the PAF-AH gene Arg92His, Ile198Thr and Ala379Val polymorphisms to resistance toward developing cardiovascular events in healthy Sicilian octogenarians. Methods: Distribution of PAF-AH genotypes and activity, and biochemical parameters, were compared between 100 octogenarians and 200 healthy adults. Results: The individuals in the elderly group displayed significantly higher levels of HDL-C (p<0.001) and plasma (p<0.001) and HDL (p<0.001) PAF-AH activity. Analysis of PAF-AH genotype distributions showed no significant differences between octogenarians and controls. No differences among PAF-AH genotypes with respect to plasma and HDL PAF-AH activity were found in either group. Conclusions: Our results provide no evidence of a significant association between the PAF-AH gene Arg92His, Ile198Thr and Ala379Val polymorphisms and successful aging in Sicilians. They also emphasize that, in these subjects, aging is characterized by increased levels of PAF-AH activity and HDL-C.

Tissue factor expression and activity are not increased in peripheral monocytes isolated from uncomplicated hypertensive patients

Background Systemic hypertension is one of the main risk factors for atherothrombosis. Tissue factor (TF) is found in the adventitia of blood vessels and in the lipid core of atherosclerotic plaques, and is specifically expressed on monocyte or macrophage cell membrane surfaces. TF plays a pivotal role in blood clotting physiology and is involved in pro-inflammatory action and atherosclerotic plaque destabilization. Objective In this study we investigated whether there is any relationship between TF messenger RNA expression and activity in blood monocytes isolated from hypertensive patients with clinical signs of atherosclerosis, uncomplicated hypertensive individuals and normotensive control subjects. Methods Eighty subjects (41 men and 39 women, mean age 41 ± 12 years) with untreated essential hypertension and 41 control subjects matched for sex and age were enrolled in the study. Patients were classified according to whether they had a normal (≤ 1 mm, 41 patients) or abnormal (> 1 mm, 39 patients) intima–media thickness (IMT). Results TF mRNA expression and activity in hypertensive individuals with no carotid atherosclerosis were no different from control subjects in unstimulated and stimulated monocytes. Abnormal IMT patients showed a higher TF mRNA expression compared with normal IMT hypertensive subjects (P < 0.001). Conclusions We demonstrated that TF mRNA and activity levels in monocytes obtained from uncomplicated hypertensive individuals are comparable with those of normotensive subjects, whereas atherosclerotic hypertensive patients showed increased levels of these parameters.

Acute effects of static stretching on jump performance

Use of stretching protocols in sport practice is widely adopted in the most part of sports. Muscular elongation is commonly accepted as a part of the warm-up and cool-down phases, as well as an important element for lowering the risk of injuries and improving the quality of performance. However several studies called the real contribution of stretching on motoric performance into doubt. The aim of our study, hence, is to further examine, through protocols and standardized measurements, acute effects of static stretching on jump performance. Sixty-two volunteer subjects (42 male, 20 female; age 21.01 ± 6.44 years; height 172.29 ± 10.55 cm; weight 64.95 ± 10.9 kg) underwent three different jump tests. According to two randomized procedures’ protocols, in non consecutive days, they executed specific static stretching exercises for lower limbs after two different warmup protocols, including (P2-Stretching) and not including (P1-No stretching) muscular elongation. Jump’s performances were recorded by Microgate OptoJump system. Data comparison after the administration of the mentioned protocols demonstrated a impairment of jump height and duration in P2-No stretching compared to P1-Stretching group (mean decrease 5.48%). Results of the present study confirm that acute static stretching lacks of positive effect on jump performance. Our results can be explained by mechanical (reduction of overlapping between actin and myosin filaments) and nervous (reset of Golgi’s muscle-tendinous organs and of neuromuscular fuses) adjustments.