Antonella Cutrone

Thrombosis and obesity: cellular bases.

The prevalence of obesity has dramatically increased during the past two decades. Epidemiological studies suggest that obesity is an independent, modifiable risk factor for coronary heart disease, possibly due, at least in part, to the development of a pro-inflammatory and a pro-thrombotic state in obese subjects. In addition, numerous cohort studies have shown a link between obesity and different types of cancer. Accordingly, the regulation of body weight is becoming a serious concern for public health experts and scientists. Although the mechanisms responsible for these associations are still to be fully elucidated, a key role has been assigned to adipokines, a family of hormones which act as modulators of metabolism or inflammation, secreted by adipocytes. Tissue factor, the major physiological trigger of the blood coagulation cascade in vivo, which plays a central role in atherothrombosis and tumor biology, has also been proposed as one of the key molecules responsible for these associations.

Inhibition of the renin-angiotensin system downregulates tissue factor and vascular endothelial growth factor in human breast carcinoma cells

INTRODUCTION The renin-angiotensin system (RAS) promotes angiogenesis and growth of neoplastic cells. Angiotensin-converting enzyme (ACE) inhibitors and angiotensin II receptor AT1 blockers may protect against cancer. Tissue factor (TF), for its involvement in tumor growth, angiogenesis, and metastasis is considered a hallmark of cancer progression. In this study we evaluated whether RAS blockade modulates TF constitutive expression by the metastatic breast carcinoma MDA-MB-231 cell line. MATERIALS AND METHODS Cell TF activity was assessed by one stage clotting time, TF and VEGF antigens and mRNA levels by ELISA and RT-PCR, respectively. AT(1) was detected by flow-cytometry and angiotensin-II levels by EIA. RESULTS Captopril reduced in a concentration-dependent way both the strong constitutive TF activity (983.2±55.2 vs. 686.7±135.1U/5×10(5) cells with 10μg/ml captopril) and antigen (32.3±5.9 vs. 13.2±6.6ng/ml) in MDA-MB-231. Similar results were observed with enalapril. AT1 was present on cell membrane and losartan, a competitive inhibitor of AT1, reduced TF expression to a degree similar as that exerted by ACE inhibitors. Moreover, captopril and losartan downregulated the constitutive mRNA TF expression by ~35%. Similar results were observed with anti-AT1 and angiotensin II antibodies. In addition, the constitutive VEGF antigen and mRNA levels were reduced in the presence of captopril or losartan, and an anti-VEGF antibody downregulated cell TF activity by ~40%. CONCLUSIONS These results could, at least in part, contribute to the discussion about the possible effects of ACE inhibitors and AT1 receptor antagonists in malignancy, and offer new clues to support their use for tumor control.

Leptin upregulates tissue factor expression in human breast cancer MCF-7 cells

INTRODUCTION Obesity is a risk factor for both cardiovascular disease and cancer development. Leptin, a cytokine produced by adipose tissue, controls different processes in peripheral tissues, including cancer development and thrombotic disorders in patients with a variety of clinical disorders. Tissue factor (TF), the trigger of blood clotting, is abundant in the adipose tissue. Since TF, often expressed by cancer cells, is considered a hallmark of cancer progression, we investigated whether leptin could modulate TF in the human metastatic breast carcinoma cell line MCF-7. MATERIALS AND METHODS MCF-7 cells were incubated with or without the different reagents at 37 °C. At the end of incubation, cells were tested for procoagulant activity by a one-stage clotting assay, TF and TNF-α antigen levels and mRNA by ELISA and real-time RT-PCR, respectively. Leptin receptor was studied by FACS. RESULTS Both TF activity and antigen constitutively expressed by MCF-7 were significantly increased by leptin in a dose-dependent fashion. TF mRNA levels were also enhanced indicating that leptin exerts its effect at the transcription level. The effect of leptin was specific and required binding to its receptor (Ob-R), which was found on the surface of the cells, since antibodies against leptin and Ob-R completely prevented TF expression upregulation. In addition, leptin enhanced both TNF-α mRNA synthesis and secretion from MCF7. An anti-TNF-α MoAb completely abolished the leptin-induced TF expression. CONCLUSIONS These data support the hypothesis that leptin, by its upregulation of TF, possibly mediated by TNF-α synthesis, may contribute to processes underlying both cancer and vascular cell disorders.

Both red and blond orange juice intake decreases the procoagulant activity of whole blood in healthy volunteers

AIM Numerous epidemiological studies suggest that exposure to flavonoid-rich fruits has beneficial influence on risk factors for cardiovascular disease. We investigated whether intake of orange juice (OJ) could affect whole blood (WB) procoagulant activity. METHODS 17 healthy subjects (aged 31 ± 1.5 SEM 10 males) were randomized to receive, according to a cross-over design, either red or blond OJ, enriched or free of anthocyanins, respectively. After one week run-in period on a controlled diet, the subjects were randomly allocated to receive either type of OJ for 4 weeks, with a 4-week wash-out period. Venous blood was collected on citrate before and at the end of each treatment period. WB was incubated with or without an inflammatory stimulus (tumor necrosis factor-α or bacterial endotoxin LPS). Procoagulant activity was evaluated by a one-stage clotting assay. Tissue factor (TF) and TF pathway inhibitor (TFPI) were measured in plasma by ELISA. RESULTS Intake of either type of OJ caused a prolongation of unstimulated and stimulated WB clotting times, without any difference between the two treatments. Intake of OJ did not modify TF levels. On the contrary, an increase in circulating TFPI antigen was detected following either treatment. CONCLUSIONS Orange juice intake by healthy volunteers decreases procoagulant activity, possibly through mechanisms independent of its anthocyanin content.

Association of proinflammatory diet with low-grade inflammation: results from the Moli-sani study

OBJECTIVES The association between diet and inflammation is well documented. Yet, no evidence exists on the relationship between the inflammatory potential of the diet and low-grade inflammation (LGI) as measured by a composite score of plasma and cellular biomarkers. The aim of this study was to assess the association between the Dietary Inflammatory Index (DII®) and LGI in a large population-based cohort. METHODS Cross-sectional analyses were conducted on data from 20 823 adults (age ≥35 y; 48% male) without acute inflammation, who were recruited within the general population of the Moli-sani study from 2005 to 2010. LGI was measured by using a composite score (INFLA-score) including platelet and leukocyte counts, the granulocyte to lymphocyte ratio, and C-reactive protein. DII scores were computed based on dietary intake assessed by the EPIC food frequency questionnaire. Multivariable linear regression models were fit to produce adjusted regression coefficients and 95% confidence intervals (CIs). RESULTS Higher DII scores were associated with increased LGI (β = 0.131; 95% CI, 0.089-0.174 for the highest versus lowest quintile of DII) after adjusting for age, sex, lifestyle, prevalence of chronic diseases, and health conditions. A higher DII score also was positively associated with each single biomarker of inflammation included in the INFLA-score, unhealthy behaviors (smoking, sedentary lifestyle), and insulin. CONCLUSIONS Higher DII scores, indicating greater inflammatory potential of the diet, were directly associated with LGI, as measured by a composite score of plasma and cellular biomarkers of inflammation. These findings are consistent with the contributing role of diet-mediated inflammation in increasing risk for inflammation-related chronic diseases.