Connective tissue cells proliferate actively when cultured in the presence of serum. Platelet-derived growth factor (PDGF), a basic protein of relative molecular mass approximately 30,000, has been identified as the major serum mitogen for these cells; its main physiological/pathophysiological role may be to initiate wound healing in connection with tissue injury. However, growth of cultured cells is also influenced by several other factors, including epidermal growth factor, fibroblast growth factor, insulin and somatomedins. Furthermore, Rozengurt and Sinnett-Smith recently showed that bombesin, a neuroendocrine peptide isolated from frog skin, stimulates DNA synthesis and cell division in cultures of a specific subtype of 3T3 cells. Substance P and substance K (also known as neurokinin A or neuromedin L) are mammalian peptides belonging to the tachykinin family. Substance P has been studied extensively; it is distributed widely throughout the central and peripheral nervous system, including primary sensory neurones, and can be released in the periphery from axon collaterals of stimulated pain fibres and contribute to the inflammatory response. Substance K is a member of the tachykinin family isolated from mammalian spinal cord; Nawa et al. determined the primary structure of two types of substance P precursors, one of which contained a sequence homologous to substance K, as well as the sequence of substance P. We report here that substance P and substance K stimulate DNA synthesis in cultured arterial smooth muscle cells and human skin fibroblasts, and that this stimulation is inhibited by the substance P-antagonist spantide.

Abstract-The aim of the present study was to analyze if LDL particles trapped in stenotic aortic valve tissue undergo oxidative modification. Degenerative aortic stenosis affects Ͼ3% of the population Ͼ75 years of age in the Western world. Recent studies have revealed the presence of a chronic inflammatory process similar to what has been described in other degenerative diseases such as atherosclerosis. However, the underlying disease mechanisms of degenerative aortic stenosis still remain largely unknown. Six tricuspid stenotic valves, obtained at valve replacement, were compared with 3 control valves collected from hearts taken out during transplantation. The stenotic valves and the control valves were examined by immunohistochemistry, using antibodies against apoB, 4-hydroxynonenal-modified LDL, leukocytes, and HLA-DR. All valves were also stained with oil red O for neutral lipids. Extracellular neutral lipids were found in all stenotic valves, extending from the bases along the fibrosa layer. This lipid colocalized with apoB-and 4-hydroxynonenal-modified LDL immunoreactivity. 4-Hydroxynonenal-modified LDLs were present around calcium deposits, subendothelially, and in the deeper layer of the fibrosa. There was also a colocalization with macrophages,

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Objective-Pleiotropic atheroprotective effects of HMG-CoA reductase inhibitors may be mediated on the level of vascular gene transcription. The aim of this study was to characterize the effects of statins on the activation of transcription factors known to regulate inflammation and cell proliferation/differentiation. Methods and Results-Simvastatin, atorvastatin, and lovastatin (0.1 to 10 mol/L) inhibited the binding of nuclear proteins to both the nuclear factor-kappa B (NF-B) and activator protein-1 (AP-1) DNA consensus oligonucleotides in human endothelial and vascular smooth muscle cells as assessed by electrophoretic mobility shift assay ( Key Words: statins Ⅲ nuclear factor-B Ⅲ activator protein-1 Ⅲ hypoxia-inducible factor-1␣ Ⅲ vascular endothelial growth factor R andomized clinical trials have clearly shown the benefit of statin therapy in the reduction of cardiovascular events and total mortality in coronary heart disease patients with either high or normal cholesterol levels. 1 In these studies, survival curves began to diverge within a relatively short period of time and before effects on plaque size were likely to occur. Demonstrated effects of HMG-CoA reductase inhibitors were not reflected by a regression in coronary stenoses as assessed by angiography. These findings have suggested that mechanisms of statins beyond lipid lowering are likely to be involved in the reduction of coronary events. 2 Both in vivo and in vitro studies support the notion that statins counteract the chronic subclinical vascular inflammatory state associated with atherosclerosis. 3,4 Statins inhibit leukocyte-endothelium interaction 5-7 and decrease inflammation in carotid lesions in humans. 8 Many of the vasculoprotective effects of HMG-CoA reductase inhibitors seem to be mediated by enhanced availability of nitric oxide. 9 There is increasing evidence that statins may act on the transcriptional level as well, eg, simvastatin inhibited endothelial secretion of PAI-1, which was correlated with reduced mRNA transcription and activity of the promoter. 10 Despite extensive research on molecular mechanisms of statins, little is known about the interactions of these drugs with transcription factors. The aim of this study was to characterize the effects of simvastatin, atorvastatin, and lovastatin on the activation of nuclear factor (NF)-B, activator protein (AP)-1, and hypoxia-inducible factor (HIF)-1␣ in endothelial and arterial smooth muscle cells. Because these factors regulate the transcription of many genes, including cytokines, chemokines, adhesion molecules, and growth factors, such interactions of statins on vascular cell signaling and gene expression may explain atheroprotective effects not directly related to cholesterol lowering. MethodsSimvastatin (MSD) and lovastatin (Calbiochem) prodrugs were activated from their inactive lactone proforms to their active dihy-