Hemorrhagic transformation of acute ischemic stroke is limited in hypertensive patients with cardiac hypertrophy.

BACKGROUND: It has been clearly demonstrated that hypertension and one of its main evoked effects, cardiac hypertrophy, are independent risk factors for ischemic stroke. However, the ischemic brain lesions can further be affected by a second wave of injury characterized by hemorrhagic transformation (HT) of the primary ischemic lesion, which significantly aggravates the clinical outcome. So far, the risk factors that could affect such a transition in hypertensive patients are still unclear. METHODS: In this study, we investigated whether in hypertensive patients the concomitant presence of cardiac hypertrophy can affect the transition of ischemic brain lesions toward HT. RESULTS: Our analysis was focused on a population of hypertensive patients admitted to our Acute Stroke Unit. The hypertensives with acute ischemic stroke suffering of HT were 18% of the sample. In these latter, the prevalence of cardiac hypertrophy was significantly lower than in those spared by HT as also shown by the levels of left ventricular mass index (LVMI) that were significantly higher in patients spared by HT. More important, cardiac hypertrophy was protective even from symptomatic HT. CONCLUSION: Here we show that hypertensive patients with cardiac hypertrophy have less probability to develop HT during an acute episode of ischemic stroke. These results could help to identify patients with lower risk of spontaneous HT and that could have better beneficial effects from thrombolytic therapy during acute ischemic stroke.

Understanding the links among neuromedin U gene, beta2-adrenoceptor gene and bone health: an observational study in European children.

Neuromedin U, encoded by the NMU gene, is a hypothalamic neuropeptide that regulates both energy metabolism and bone mass. The beta-2 adrenergic receptor, encoded by the ADRB2 gene, mediates several effects of catecholamine hormones and neurotransmitters in bone. We investigated whether NMU single nucleotide polymorphisms (SNPs) and haplotypes, as well as functional ADRB2 SNPs, are associated with bone stiffness in children from the IDEFICS cohort, also evaluating whether NMU and ADRB2 interact to affect this trait. A sample of 2,274 subjects (52.5% boys, age 6.2 ± 1.8 years) from eight European countries, having data on calcaneus bone stiffness index (SI, mean of both feet) and genotyping (NMU gene: rs6827359, rs12500837, rs9999653; ADRB2 gene: rs1042713, rs1042714), was studied. After false discovery rate adjustment, SI was significantly associated with all NMU SNPs. rs6827359 CC homozygotes showed the strongest association (recessive model, Δ= -1.8, p=0.006). Among the five retrieved haplotypes with frequencies higher than 1% (range 2.0-43.9%), the CCT haplotype (frequency=39.7%) was associated with lower SI values (dominant model, Δ= -1.0, p=0.04) as compared to the most prevalent haplotype. A non-significant decrease in SI was observed in in ADRB2 rs1042713 GG homozygotes, while subjects carrying SI-lowering genotypes at both SNPs (frequency = 8.4%) showed much lower SI than non-carriers (Δ= -3.9, p<0.0001; p for interaction=0.025). The association was more evident in preschool girls, in whom SI showed a curvilinear trend across ages. In subgroup analyses, rs9999653 CC NMU or both GG ADRB2 genotypes were associated with either lower serum calcium or ß-CrossLaps levels (p=0.01). This study in European children shows, for the first time in humans, a role for NMU gene through interaction with ADRB2 gene in bone strength regulation, more evident in preschool girls.

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.

From candidate gene to genome-wide association studies in cardiovascular disease.

Continuous updating of the genotyping technology has led to improvement of genetic study design. The recent advances in technology coupled with the advances in our understanding of the molecular mechanisms have allowed a more comprehensive examination of the role of genetics, environment and their interaction in determining the individual risk of cardiovascular disease (CVD). Initial candidate gene studies identified a limited number of polymorphisms associated with disease, explaining only a minor part of trait variance. Furthermore, results were not often concordant, with meta-analyses not reaching the statistical power to confirm an association in many cases. The advent of the genome-wide design furnished an enormous quantity of information and decreased time of genotyping, while increased complexity of analyses and costs. Their results were more concordant, even when they suggested associations between CVD and polymorphisms distant from codifying regions or in genes involved in previously unsuspected pathways. Future results from genome-wide studies coupled with results from functional studies and investigation on gene-environment interactions will allow improvement of cardiovascular risk assessment and discovery of new targets for therapy and prevention. In this review, a brief history of cardiovascular genetics is reported, from candidate gene to genome wide association studies, that led to the identification of association between CVD and SNPs in the 9p21 region, firstly thought a gene desert without importance.

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.

White blood cell count, sex and age are major determinants of heterogeneity of platelet indices in an adult general population: results from the MOLI-SANI project.

BACKGROUND: The understanding of non-genetic regulation of platelet indices--platelet count, plateletcrit, mean platelet volume, and platelet distribution width--is limited. The association of these platelet indices with a number of biochemical, environmental and clinical variables was studied in a large cohort of the general population. DESIGN AND METHODS: Men and women (n=18,097, 52% women, 56±12 years) were randomly recruited from various villages in Molise (Italy) in the framework of the population-based cohort study "Moli-sani". Hemochromocytometric analyses were performed using an automatic analyzer (Beckman Coulter, IL, Milan, Italy). Associations of platelet indices with dependent variables were investigated by multivariable linear regression analysis. RESULTS: Full models including age, sex, body mass index, blood pressure, smoking, menopause, white and red blood cell counts, mean corpuscular volume, D-dimers, C-reactive protein, high-density lipoproteins, low-density lipoproteins, triglycerides, glucose, and drug use explained 16%, 21%, 1.9% and 4.7% of platelet count, plateletcrit, mean platelet volume and platelet distribution width variability, respectively; variables that appeared to be most strongly associated were white blood cell count, age, and sex. Platelet count, mean platelet volume and plateletcrit were positively associated with white blood cell count, while platelet distribution width was negatively associated with white blood cell count. Platelet count and plateletcrit were also positively associated with C-reactive protein and D-dimers (P<0.0001). Each of the other variables, although associated with platelet indices in a statistically significant manner, only explained less than 0.5% of their variability. Platelet indices varied across Molise villages, independently of any other platelet count determinant or characteristics of the villages. CONCLUSIONS: The association of platelet indices with white blood cell count, C-reactive protein and D-dimers in a general population underline the relation between platelets and inflammation.