Circulating progenitor cells and the elderly: a seven-year observational study.

Cardiovascular (CV) diseases and related complications are the main causes of morbidity and mortality in the elderly. CV progenitor cells, including CD34+ cells, play a role in delaying the progression of atherosclerosis. In the present study we observed 100 octogenarians for seven years, in order to address the question of whether CD34+ cell number is a predictor of longevity in selected survivors. We also checked for associations of cell expression of manganese superoxide dismutase (Mn-SOD), catalase (CAT), and glutathione peroxidase type-1 (GPx-1) antioxidative enzymes, with number of CD34+ progenitor cells and mortality. We found that in very old subjects the number of CD34+ cells at baseline were higher in subjects who reached older age at death or were still living at the end of observation period, with respect to subjects who died from all causes, including CV deaths. On the other hand, HDL-C plasma levels and, with the exception of diabetes, the classic CV risk factors (hypertension, smoking, hypercholesterolemia) showed a loss of their predictive power. A significant association between the redox system of CD34+ cells and mortality was also observed. These data suggest that, even in the elderly, CD34+ cells maintain their role in predicting mortality. CD34+ cells could thus be considered as a biomarker of longevity.

Circulating progenitor cells are increased in newly diagnosed untreated hypertensive patients with arterial stiffening but normal carotid intima-media thickness.

Circulating progenitor cells (CPCs), including endothelial progenitor cells (EPCs), have a key role in endothelium repair. Cellular NADPH oxidase (Nox) enzymes, including Nox-containing gp91phox, represent a source of reactive oxygen species (ROS); ROS trigger protective signals but may also have detrimental effects. Cellular defenses against ROS include the enzymes manganese superoxide dismutase (MnSOD), catalase (CAT) and glutathione peroxidase type-1 (GPx-1). We investigated the relationships of CPCs with cellular gp91phox, MnSOD, CAT, GPx-1 and ROS levels and with carotid intima-media thickness (cIMT) and stiffness in hypertensives without additional risk factors for cardiovascular disease. CPCs from 53 newly diagnosed, untreated hypertensives and from 29 controls were isolated and identified by flow cytometry. gp91phox, MnSOD, CAT, and GPx-1 mRNA and protein expression and ROS generation were evaluated in enriched samples of CD34(+) cells; cIMT and stiffness were assessed. Hypertensives showed higher arterial stiffness (P < 0.001) but no difference in cIMT with respect to controls. ROS generation was slightly increased (P=0.04), whereas gp91phox, MnSOD, CAT and GPx-1 were significantly higher (P < 0.001) with respect to controls, as was CPC number (P < 0.001), but EPCs were no different. CPC and EPC numbers correlated with gp91phox, ROS and fibrinogen (P < 0.001); moreover, gp91phox, MnSOD, CAT and GPx-1 were correlated with CPC number. In early phases of arterial hypertension, before the development of wall thickening and even in the presence of arterial mechanical impairment, CPC number may be increased to maintain an adequate number of EPCs in peripheral blood.

Smoke exposure and circulating progenitor cells: evidence for modulation of antioxidant enzymes and cell count.

BACKGROUND: Cigarette smoking is involved in vascular inflammation and impairment of circulating progenitor cells (CPCs), including endothelial progenitor cells (EPCs). The study aim was to evaluate the redox balance of these cells in relation to smoking exposure. METHODS: Circulating cells from 36 healthy smokers and 26 controls were isolated and identified by flow cytometry. ROS generation, mRNA and protein cell expression, and enzymatic activity of MnSOD, catalase, and GPx-1 were evaluated. RESULTS: Smokers showed higher levels of CRP and fibrinogen and lower levels of HDL-C. ROS and MnSOD were higher (p<0.001), while catalase and GPx-1 were lower (p<0.001) as was EPC number (p<0.001) in smokers. CPC and EPC correlated with HDL-C, CRP, ROS and enzyme expression and activity. CONCLUSIONS: Our data suggest that smoking exposure involves antioxidant enzymes in CPCs and EPCs and that the inflammatory response in smokers plays an important role in impairing cells and their antioxidant functions.

Assessment of liver stiffness in subjects affected by familial combined hyperlipidaemia with hepatic steatosis.

BACKGROUND: Nonalcoholic fatty liver disease (NAFLD) represents a spectrum of diseases ranging from simple steatosis to nonalcoholic steatohepatitis (NASH) and is associated with familial combined hyperlipidaemia (FCHL). Currently, the invasive liver biopsy is considered as the gold standard for evaluating liver fibrosis (LF); however, liver stiffness measurement (LSM) by transient elastography (TE) trough FibroScan device may be employed to estimate LF noninvasively. The aim of this study was to evaluate the prevalence of NAFLD in FCHL subjects and to analyse LSM with TE to better identify those individuals with a potential risk of liver disease progression. MATERIALS AND METHODS: Sixty subjects with FCHL (38 men, 22 women, mean age 46.4 +/- 10.9 years) were included in the study. We studied biochemical parameters including lipid profile, glucose, transaminase and insulin; blood pressure and waist circumference (WC) were measured; BMI and HOMA-index were calculated. Ultrasonography was performed to assess liver steatosis and carotid intima-media thickness (IMT). Liver fibrosis was measured by FibroScan. RESULTS: Patients were classified according to have no (group 0: 19%), mild (group 1: 32%) or moderate-severe (group 2: 49%) steatosis. No difference was found between group 0 and 1 concerning all study parameters. WC (P < 0.05), BMI (P < 0.05), glucose (P < 0.05), insulin (P < 0.001), HOMA-index (P < 0.001) and LSM (6.03 +/- 1.9 Kpa vs. 4.2 +/- 0.5 Kpa, P < 0.001) were significantly higher in group 2 than groups 1 and 0. Furthermore, LSM correlated with insulin (P < 0.05), glucose (P < 0.05), HOMA-index (P < 0.001), transaminase (P < 0.01) and liver steatosis (P < 0.001). Regression analysis showed that LSM (P < 0.001) and NAFLD (P < 0.01) is associated with HOMA-index; NAFLD is also associated with WC (P < 0.05). CONCLUSION: Our results suggest that in FCHL subjects, HOMA-index, an insulin resistance index, is strongly associated with liver steatosis and its progression. Furthermore, in these subjects, we propose the transient elastography to identify and follow up patients for the progression of hepatic disease.

Effects of the angiotensin II receptor blocker losartan on the monocyte expression of biglycan in hypertensive patients.

1. Recently, we demonstrated that biglycan (BGN) is increased in circulating monocyte cells from hypertensive patients and that angiotensin (Ang) II is able to increase BGN expression. The present study was designed to investigate the effects of treatment with the angiotensin AT(1) receptor antagonist losartan on monocyte BGN mRNA and protein expression in essential hypertension. 2. One hundred and twenty-six newly diagnosed hypertensive patients without additional risk factors for atherosclerosis and cardiovascular disease were treated with 100 mg losartan once daily for 6 months. Biglycan mRNA and protein expression was determined in monocytes isolated from peripheral blood before (T(0)) and after (T(1)) therapy. Plasma levels of interleukin (IL)-6, tumour necrosis factor (TNF)-alpha and high sensitivity C-reactive protein (hs-CRP) were also determined. In addition, BGN mRNA and protein expression was determined after the ex vivo addition of 1 micromol/L AngII to monocytes isolated from 20 randomly selected hypertensive patients. 3. Biglycan mRNA and protein expression, blood pressure and plasma levels of fibrinogen, IL-6, TNF-alpha and CRP were significantly lower at T(1) than at T(0). Variations in BGN expression were associated with inflammatory markers, but not directly with blood pressure. In AngII-stimulated monocytes, BGN mRNA and protein expression was significantly lower at T(1) that at T(0). Moreover, mean BGN mRNA expression in AngII-stimulated monocytes isolated from losartan-treated patients was similar to baseline expression in unstimulated monocytes from untreated patients. 4. The results of the present study show that losartan can reduce BGN expression in monocytes from hypertensive patients, without any linear association with blood pressure, suggesting that the effects of AngII on BGN expression in monocytes may be modulated, in part, by an AT(1) receptor blocker.

Biglycan expression in hypertensive subjects with normal or increased carotid intima-media wall thickness.

BACKGROUND: Biglycan (BGN), an extracellular matrix proteoglycan, has been shown to convey pro-inflammatory signals. In the present study we investigated BGN expression and its correlation with plasma levels of inflammatory markers in hypertensive subjects with or without alteration of carotid intima media thickness (IMT). METHODS: We evaluated 123 untreated essential hypertensives with no additional risk factors for atherosclerosis nor signs of cardiovascular disease and 40 controls. Hypertensives were classified according to a normal (< or =1 mm) or increased (>1 mm) IMT. BGN-mRNA and protein expression were measured in unstimulated, LPS- and Angiotensin II (Ang-II)-stimulated blood monocytes. Plasma concentrations of interleukin-6 (IL-6), tumor necrosis factor alpha (TNF-alpha) and high sensitivity-C-reactive protein (hs-CRP) were also measured. RESULTS: We found increased levels of IL-6, TNF-alpha, hs-CRP, and BGN-mRNA and protein in hypertensives vs controls (1.72+/-0.60 vs 1 n-fold, and 3.60+/-0.75 vs 1 n-fold, both p<0.001). However, BGN expression was not significantly different between hypertensives with IMT < or =1 mm and >1 mm. Furthermore, in vitro addition of Ang II enhanced basal BGN-mRNA (in hypertensives: 3.57+/-1.08 vs 1.72+/-0.60 n-fold, p<0.001) and protein (in hypertensives: 4.92+/-0.42 vs 3.41+/-0.75, p<0.001) expression in monocytes. CONCLUSIONS: Our data provide evidence of an enhanced expression of BGN in essential hypertension. In addition we suggest that Ang II can mediate monocyte BGN production.

Association between serum paraoxonase (PON1) gene promoter T(-107)C polymorphism, PON1 activity and HDL levels in healthy Sicilian octogenarians.

Age is associated with an enhanced low density lipoprotein (LDL) oxidation and atherosclerosis, thus, subjects over 80 years without cardiovascular disease provide a model to investigate the protective factors against atherosclerosis. Serum paraoxonase (PON1), an high density lipoprotein (HDL)-bound enzyme, prevents LDL oxidation. The aim of the present study was to evaluate the contribution of the PON1 promoter T(-107)C and coding region Gln192Arg (Q192R) and Leu55Met (L55M) polymorphisms to the resistance to develop cardiovascular events in Sicilian healthy octogenarians. Distribution of PON1 genotypes and activity, and biochemical parameters, were compared between 100 octogenarians and 200 adults. Individuals in the elderly group displayed significant higher levels of HDL-C (P < 0.001) and PON1 activity (P < 0.001). The analysis of PON1 genotypes distribution showed an higher percentage of (-107)CC among octogenarians compared with controls. A significant difference among T(-107)C genotypes respect to PON1 activity and HDL-C levels occurred in both groups. The CC genotype was associated with higher PON1 activity and HDL levels compared to the TT genotypes. In conclusion, our results provide a strong evidence that in healthy Sicilians ageing may be characterized by a low frequency of PON1 (-107)T 'risk' allele and by an high frequency of favourable genotypes such as (-107)CC, influencing PON1 activity and HDL-C levels.