Human respiratory syncytial virus (RSV) causes a large burden of disease worldwide. There is no effective vaccine or therapy, and the use of passive immunoprophylaxis with RSV-specific antibodies is limited to high-risk patients. The cellular receptor (or receptors) required for viral entry and replication has yet to be described; its identification will improve understanding of the pathogenesis of infection and provide a target for the development of novel antiviral interventions. Here we show that RSV interacts with host-cell nucleolin via the viral fusion envelope glycoprotein and binds specifically to nucleolin at the apical cell surface in vitro. We observed decreased RSV infection in vitro in neutralization experiments using nucleolin-specific antibodies before viral inoculation, in competition experiments in which virus was incubated with soluble nucleolin before inoculation of cells, and upon RNA interference (RNAi) to silence cellular nucleolin expression. Transfection of nonpermissive Spodoptera frugiperda Sf9 insect cells with human nucleolin conferred susceptibility to RSV infection. RNAi-mediated knockdown of lung nucleolin was associated with a significant reduction in RSV infection in mice (P = 0.0004), confirming that nucleolin is a functional RSV receptor in vivo.

OBJECTIVE-Leukocyte adhesion in retinal microvasuculature substantially contributes to diabetic retinopathy. Involvement of the Rho/Rho kinase (ROCK) pathway in diabetic microvasculopathy and therapeutic potential of fasudil, a selective ROCK inhibitor, are investigated. RESEARCH DESIGN AND METHODS-Localization ofRhoA/ROCK and Rho activity were examined in retinal tissues of rats. Impact of intravitreal fasudil administration on retinal endothelial nitric oxide synthase (eNOS) and myosin phosphatase target protein (MYPT)-1 phosphorylation, intercellular adhesion molecule-1 (ICAM-1) expression, leukocyte adhesion, and endothelial damage in rat eyes were investigated. Adhesion of neutrophils from diabetic retinopathy patients or nondiabetic control subjects to cultured microvascular endothelial cells was quantified. The potential of fasudil for endothelial protection was investigated by measuring the number of adherent neutrophils and terminal transferase-mediated dUTP nick-end labeling-positive endothelial cells.RESULTS-RhoA and ROCK colocalized predominantly in retinal microvessels. Significant Rho activation was observed in retinas of diabetic rats. Intravitreal fasudil significantly increased eNOS phosphorylation, whereas it reduced MYPT-1 phosphorylation, ICAM-1 expression, leukocyte adhesion, and the number of damaged endothelium in retinas of diabetic rats. Neutrophils from diabetic retinopathy patients showed significantly higher adhesion to cultured endothelium and caused endothelial apoptosis, which was significantly reduced by fasudil. Blockade of the Fas-FasL interaction prevented endothelial apoptosis. The protective effect of fasudil on endothelial apoptosis was significantly reversed by N-nitro-L-arginine methyl ester, a NOS inhibitor, whereas neutrophil adhesion remained unaffected. CONCLUSIONS-The

Metabolic syndrome (MetS) is a prevalent and complex disease, characterized by the variable coexistence of obesity, dyslipidemia, hyperinsulinaemia, and hypertension. The alarming rise in the prevalence of metabolic disorders makes it imperative to innovate preventive or therapeutic measures for MetS and its complications. However, the elucidation of the pathogenesis of MetS has been hampered by the lack of realistic models. For example, the existing animal models of MetS, i.e., genetically engineered rodents, imitate certain aspects of the disease, while lacking other important components. Defining the natural course of MetS in a spontaneous animal model of the disease would be desirable. Here, we introduce the Nile grass rat (NGR), Arvicanthis niloticus, as a novel model of MetS. Studies of over 1100 NGRs in captivity, fed normal chow, revealed that most of these animals spontaneously develop dyslipidemia (P<0.01), and hyperglycemia (P<0.01) by 1 yr of age. Further characterization showed that the diabetic rats develop liver steatosis, abdominal fat accumulation, nephropathy, atrophy of pancreatic islets of Langerhans, fatty streaks in the aorta, and hypertension (P<0.01). Diabetic NGRs in the early phase of the disease develop hyperinsulinemia, and show a strong inverse correlation between plasma adiponectin and HbA1c levels (P<0.01). These data indicate that the NGR is a valuable, spontaneous model for exploring the etiology and pathophysiology of MetS as well as its various complications.