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An inflammatory response followed by vascular injury plays an important role in neointima formation and development of atherosclerotic lesions, which are in part mediated by proinflammatory cytokines. Using a cuff injury model, we examined the effects of adenovirus-mediated overexpression of phosphatase and tensin homology deleted on chromosome 10 (PTEN) on neointima formation and the proinflammatory response. A cuff was placed around the femoral artery, and adenovirus expressing human PTEN type 1 (AdPTEN) or Escherichia coli [beta]-galactosidase (AdLacZ) was injected between the cuff and the adventitia. After 14 days, the arteries were examined histopathologically and by Western blotting. The significant reduction of neointima formation by AdPTEN compared with AdLacZ was accompanied by reduced cell proliferation and increased adventitial cell apoptosis. AdPTEN also reduced expression of phosphorylated I[kappa]B-[alpha], but not nonphosphorylated I[kappa]B-[alpha]. Western blotting revealed that AdPTEN reduced the cuff injury-induced expression levels of monocyte chemoattractant protein-l, TNF-[alpha], and IL-1[beta] and their expression in all layers of the arterial wall. In contrast, cuff-induced macrophage invasion, which was also inhibited by AdPTEN, was detected only at the intimal surface and in the adventitia. In cultured vascular smooth muscle cells, PTEN 'directly inhibited ANG II-induced monocyte chemoattractant protein-1 expression as quantified by real-time PCR and Western blotting. Our results suggest that overexpression of PTEN reduces neointima formation, possibly in part through inhibition of the inflammatory response by macrophage invasion and proinflammatory cytokine expression. vascular inflammation; monocyte chemoattractant protein-1; gene transfer doi:10.1152/ajpheart.01221.2006

The article focuses on the role of Menkes Adenosine triphosphatase (MNK) in hypertension induced by angiotensin II. It states that extracellular superoxide dismutase (SOD3) regulates angiotensin II by modulating SOD3 levels. It mentions that chronic angiotensin II infusion enhances the vascular superoxide anion production and systolic blood pressure in MNK mutant mice. It states that coimmunoprecipitation analysis found that angiotensin II stimulation promoted an association of MNK with SOD3.

Copper plays a fundamental role in regulating cell growth. Many types of human cancer tissues have higher copper levels than normal tissues. Copper can also induce gene expression. However, transcription factors that mediate copper-induced cell proliferation have not been identified in mammals. Here we show that antioxidant-1 (Atox1), previously appreciated as a copper chaperone, represents a novel copper-dependent transcription factor that mediates copper-induced cell proliferation. Stimulation of mouse embryonic fibroblasts (MEFs) with copper markedly increased cell proliferation, cyclin D1 expression, and entry into S phase, which were completely abolished in Atox1-/- MEFs. Promoter analysis and EMSA revealed that copper stimulates the Atox1 binding to a previously undescribed cis element in the cyclin D1 promoter. The ChIP assay confirms that copper stimulates Atox1 binding to the DNA in vivo. Transfection of Atox1 fused to the DNA-binding domain of Gal4 demonstrated a copper-dependent transactivation in various cell types, including endothelial and cancer cells. Furthermore, Atox1 translocated to the nucleus in response to copper through its highly conserved C-terminal KKTGK motif and N-terminal copper-binding sites. Finally, the functional role of nuclear Atox1 is demonstrated by the observation that re-expression of nuclear-targeted Atox1 in Atox1 MEFs rescued the defective copper-induced cell proliferation. Thus, Atox1 functions as a novel transcription factor that, when activated by copper, undergoes nuclear translocation, DNA binding, and transactivation, thereby contributing to cell proliferation. [ABSTRACT FROM AUTHOR]

Tumor survival depends in part on the ability of tumor cells to transform the surrounding extracellular matrix (ECM) into an environment conducive to tumor progression. Matricellular proteins are secreted into the ECM and impact signaling pathways that are required for pro-tumorigenic activities such as angiogenesis. Fibulin-5 (Fbln5) is a matricellular protein that was recently shown to regulate angiogenesis; however, its effect on tumor angiogenesis and thus tumor growth is currently unknown. We report that the growth of pancreatic tumors and tumor angiogenesis is suppressed in Fbln5-null (Fbln5(-/-)) mice compared with wild-type (WT) littermates. Furthermore, we observed an increase in the level of reactive oxygen species (ROS) in tumors grown in Fbln5(-/-) animals. Increased ROS resulted in elevated DNA damage, increased apoptosis of endothelial cells within the tumor, and represented the underlying cause for the reduction in angiogenesis and tumor growth. In vitro, we identified a novel pathway by which Fbln5 controls ROS production through a mechanism that is dependent on beta1 integrins. These results were validated in Fbln5(RGE/RGE) mice, which harbor a point mutation in the integrin-binding RGD motif of Fbln5, preventing its interaction with integrins. Tumor growth and angiogenesis was reduced in Fbln5(RGE/RGE) mice, however treatment with an antioxidant rescued angiogenesis and elevated tumor growth to WT levels. These findings introduce a novel function for Fbln5 in the regulation of integrin-induced ROS production and establish a rationale for future studies to examine whether blocking Fbln5 function could be an effective anti-tumor strategy, alone or in combination with other therapies.

Objective: Three-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) are known to enhance vascular expression of endothelial (eNOS) and inducible nitric oxide synthase (iNOS). In this study, we examined whether statins also upregulate vascular expression of neuronal NOS (nNOS)., Methods and Results: In cultured rat aortic smooth muscle cells, treatment with atorvastatin significantly increased nNOS expression, associated with activation of Akt and NF-kappaB. Inhibition of Akt by dominant-negative Akt suppressed atorvastatin-induced nNOS expression as well as Akt and NF-kappaB activation. Inhibition of NF-kappaB by dominant-negative IkappaB also attenuated atorvastatin-induced nNOS expression and NF-kappaB activation, but not Akt activation. We further examined whether atorvastatin also enhances nNOS expression in isolated mouse aorta, and if so, how much nNOS-derived NO accounts for atorvastatin-induced NOx production. In isolated aortas of wild-type mice, atorvastatin significantly increased all three NOS isoform expression and NOx production. In isolated aortas of doubly i/eNOS(-/-), n/eNOS(-/-), and n/iNOS(-/-) mice, which express only nNOS, iNOS, and eNOS, respectively, atorvastatin-induced NOx production was approximately 25%, 25%, and 50% to that of wild-type mice, respectively, suggesting that nNOS accounts for 25% of the atorvastatin-mediated NOx production., Conclusions: These results indicate that atorvastatin upregulates vascular nNOS through Akt/NF-kappaB pathway, demonstrating a novel nNOS-mediated vascular effect of the statin.