Vitamin C suppresses lipopolysaccharide-induced procoagulant response of human monocyte-derived macrophages.

OBJECTIVE: Although vitamin C is a strong antioxidant, the epidemiologic evidence to support its role in lowering risk of cardiovascular disease is inconsistent. In order to define the role of vitamin C in vascular pathophysiology, we have investigated the effect of vitamin C on the tissue factor (TF) and Factor VII Activating Protease (FSAP) expression induced by lipopolysaccharide (LPS) in human monocyte-derived macrophages. MATERIALS AND METHODS: Vitamin C at clinically relevant doses was tested to its ability to influence the LPS- and reactive oxygen species (ROS) - generating system of xanthine/xanthine oxidase (X/XO) NF-kB activity in human monocyte-derived macrophages. RESULTS: Vitamin C-treatment prevents LPS- and ROS-induced DNA-binding activity of NF-kB in a concentration-dependent fashion. Vitamin C also inhibited the phosphorylation and proteolytic degradation of the inhibitor protein IkBa. In parallel to regulate NF-kB activity, vitamin C reduced the expression of TF and FSAP, genes known to be induced by bacterial LPS and triggered the extrinsic coagulation cascade and linked thrombosis with inflammation. CONCLUSIONS: Vitamin C alters pro-inflammatory and pro-coagulatory processes via inhibition of NF-kB activation and exerts beneficial antiatherogenic effects on human monocyte-derived macrophages in addition to its anti-oxidant properties.

Whole genome DNA methylation signature of HER2-positive breast cancer.

In order to obtain a comprehensive DNA methylation signature of HER2-positive breast cancer (HER2+ breast cancer), we performed a genome-wide methylation analysis on 17 HER2+ breast cancer and compared with ten normal breast tissue samples using the Illumina Infinium HumanMethylation450 BeadChip (450K). In HER2+ breast cancer, we found altered DNA methylation in genes involved in multicellular development, differentiation and transcription. Within these genes, we observed an overrepresentation of homeobox family genes, including several genes that have not been previously reported in relation to cancer (DBX1, NKX2-6, SIX6). Other affected genes included several belonging to the PI3K and Wnt signaling pathways. Notably, HER2, AKT3, HK1, and PFKP, genes for which altered methylation has not been previously reported, were also identified in this analysis. In total, we report 69 candidate biomarker genes with maximum differential methylation in HER2+ breast cancer. External validation of gene expression in a selected group of these genes (n = 13) revealed lowered mean gene expression in HER2+ breast cancer. We analyzed DNA methylation in six top candidate genes (AKR1B1, INA, FOXC2, NEUROD1, CDKL2, IRF4) using EpiTect Methyl II Custom PCR Array and confirmed the 450K array findings. Future clinical studies focusing on these genes, as well as on homeobox-containing genes and HER2, AKT3, HK1, and PFKP, are warranted which could provide further insights into the biology of HER2+ breast cancer.

Inertially assisted nanoscale self-assembly.

We present a simple and versatile method for integrating submicron objects onto pre-determined locations on a substrate. The method relies on augmenting inertial forces using centrifugal motion and geometric constraints to guide the placement of submicron objects on a substrate with minimal requirements for surface engineering and binding chemistries. Here, we demonstrate the utility of the method for placing gold particles, metal nanorods and inorganic nanocrystals. The method has demonstrated high yield of self-assembly for submicron particles with a variety of shapes and sizes. We have been able to get a near-perfect yield for filling hundreds of traps with nanoparticles in only 20 min. Two hundred nanometer diameter nanorods were self-assembled into an array of 256 traps on the template with 92% yield. 1.4 microm and 300 nm sodium chloride crystals were self-assembled in arrays of 7000 and 576 traps, respectively, with near-perfect yield in filling each site. Due to its convenient set-up and high performance, inertially assisted self-assembly can be easily adopted and used for a variety of integration needs on the submicron scale.

A Fully Integrated RF-Powered Contact Lens With a Single Element Display.

We present progress toward a wirelessly-powered active contact lens comprised of a transparent polymer substrate, loop antenna, power harvesting IC, and micro-LED. The fully integrated radio power harvesting and power management system was fabricated in a 0.13 µm CMOS process with a total die area of 0.2 mm(2). It utilizes a small on-chip capacitor for energy storage to light up a micro-LED pixel. We have demonstrated wireless power transfer at 10 cm distance using the custom IC and on-lens antenna.

Statins differ in their ability to block NF-kappaB activation in human blood monocytes.

OBJECTIVE: The benefits of statin therapy in cardiovascular medicine are ascribed to its lipid-lowering effect as well as its anti-inflammatory properties. Whereas all statins have been shown to reduce cholesterol plasma levels, their effect on inflammatory markers has been inconsistent. Here, we show that statins differ markedly in their effectiveness in preventing activation of NF-kappaB, a transcription factor involved in the activation of immediately early genes during inflammation. METHODS: Six statins (atorvastatin (Atv), cerivastatin (Cer), fluvastatin (Flu), lovastatin (Lov), pravastatin (Pra), simvastatin (Sim)) were tested for their ability to influence the induction of NF-kappaB in human monocytes (Mo) during inflammation. Mo isolated from healthy blood donors were incubated with LPS (10 microg/ml) in the presence and absence of statin (0.001-5 microM). NF-kappaB binding activity (EMSA), degradation and phosphorylation of the inhibitor protein IkappaB-alpha (Western blotting), tissue factor (TF) mRNA (rtPCR), and TF activity (clotting assay) were analyzed. RESULTS: All statins inhibited LPS-induced NF-kappaB binding activity in Mo in a dose-dependent manner. The inhibitory effect was due to reduced phosphorylation and degradation of the NF-kappaB inhibitor protein IkappaB, and was primarily dependent on the absence of mevalonate. Whilst this effect appeared with all statins, there were marked differences in the degree of inhibition between the statins. Cer (45 +/- 9% inhibition, p < 0.05) was 9-fold more effective in reducing NF-kappaB activation than Flu (5 +/- 10% inhibition). The differences in the potency of statins (Cer > Atv > Sim > Pra > Lov > Flu) were also reflected at the transcriptional level and the protein level of NF-kappaB controlled tissue factor expression. CONCLUSIONS: The finding that statins differ in their potency in interfering with the activation of NF-kappaB signaling in human monocytes further supports the hypothesis that some statins inhibit the inflammatory response more than others.

Monocyte tissue factor expression is enhanced in women who smoke and use oral contraceptives.

The association between use of oral contraceptives (OCs) and increased risk of thromboembolic disease has been firmly established. This risk increases when use of OCs is combined with cigarette smoking. The cellular mechanism favoring an hypercoagulable state under these behaviours is not known. Circulating monocytes are potent activators of the coagulation cascade through their ability to synthesize procoagulant tissue factor (TF). In the present study we report that monocyte TF expression is increased in women who use OCs and smoke. We studied monocyte TF expression in 4 groups of healthy pre-menopausal women (n = 15 each): (1) non-smoking OC non-users, (2) nonsmoking current OC users, (3) smoking OC non-users and (4) smoking OC users. TF expression was assessed on both mRNA and protein levels in unstimulated and LPS-stimulated cells. Transcriptional activation of the TF gene was assessed by analysis of the transcription factor NF-kappaB and its inhibitor molecule IkappaBalpha. Monocyte TF generation was significantly higher in OC users than in women who did not use OCs. Enhanced monocyte TF generation was also observed in smoking women when compared to non-smokers. Strongest monocyte TF expression occurred in women with combined smoking and use of OCs. The enhanced TF expression in monocytes from women using OCs or smoking was based on an increased TF gene transcription following activation of NF-kappaB. Experiments on cultured monocytes/macrophages demonstrated enhanced IkappaBalpha degradation in the presence of estradiol, suggesting that a direct hormone effect is responsible for the observed increase in monocyte TF expression. This study demonstrates that use of OCs and smoking is associated with an increase in monocyte TF expression in pre-menopausal women. Aberrant TF expression by blood monocytes may favour intravascular clotting activation in women with OC therapy. The further enhancement of TF activity observed in women who smoke and use OCs may explain the synergistic effect of smoking on risk of thromboembolic events associated with contraceptive use.

The role of decreased retinoblastoma protein expression in acute myelomonocytic and monoblastic leukemias.

The results of different investigators show that lack of p105 expression is relatively common in human myeloid leukemias, especially in monocytic leukemias. This suggests that loss of p105 expression could contribute to the altered growth control of these cells. So far no clear data exist which show that low p105 levels in AML blasts predict a poor therapy outcome. Therefore it is not very likely that p105 expression will become a strong prognostic factor for the different treatment strategies in AML.

Altered expression of the human retinoblastoma gene in monocytic leukaemias.

Inactivation of the retinoblastoma growth suppressor gene (RB) is responsible for the development of retinoblastomas and occurs frequently in osteosarcomas and small cell lung carcinoma. Knowledge about the involvement of RB in the pathogenesis of myeloid leukaemias is still scarce. In this study we looked at the expression of the retinoblastoma gene product (p105) in 20 primary myelomonocytic and monoblastic leukaemias by Western blotting and immunocytochemistry using the anti-p105-monoclonal antibody PMG3-245. We found absence of or barely detectable levels of p105 in 11 patients (55%). Absence of or low levels of p105 were correlated with a higher leucocyte count at presentation (133 x 10(9)/l v 83 x 10(9)/l) and with the occurrence of extramedullary leukaemia (8/10 v 2/10). We conclude that abnormal expression of RB with absence of p105 or strongly reduced p105 levels occurs frequently in myelomonocytic and monoblastic leukaemias and that this may be correlated with a more malignant course of the disease.