Respiratory syncytial virus (RSV) infection is one of the major causes of respiratory tract infection for which no vaccine or antiviral treatment is available. The RSV NS1 protein seems to antagonize the host interferon (IFN) response; however, its mechanism is unknown. Here, we used a plasmid-borne small interfering RNA targeting the NS1 gene (siNS1) to examine the role of NS1 in modulating RSV infection. RSV replication was reduced in A549 cells, but not IFN-deficient Vero cells, transfected with siNS1. siNS1 induced upregulated expression of IFN-beta and IFN-inducible genes in A549 cells. siNS1-transfected human dendritic cells, upon RSV infection, produced elevated type-1 IFN and induced differentiation of naive CD4+ T cells to T helper type 1 (TH1) cells. Mice treated intranasally with siNS1 nanoparticles before or after infection with RSV showed substantially decreased virus titers in the lung and decreased inflammation and airway reactivity compared to controls. Thus, siNS1 nanoparticles may provide an effective inhibition of RSV infection in humans.

Traumatic injury to the brain (TBI) results in a complex set of responses involving various symptoms and long-term consequences. TBI of any form can cause cognitive, behavioral and immunologic changes in later life, which underscores the problem of underdiagnosis of mild TBI that can cause long-term neurological deficits. TBI disrupts the blood–brain barrier (BBB) leading to infiltration of immune cells into the brain and subsequent inflammation and neurodegeneration. TBI-induced peripheral immune responses can also result in multiorgan damage. Despite worldwide research efforts, the methods of diagnosis, monitoring and treatment for TBI are still relatively ineffective. In this review, we delve into the mechanism of how TBI-induced central and peripheral immune responses affect the disease outcome and discuss recent developments in the continuing effort to combat the consequences of TBI and new ways to enhance repair of the damaged brain.

The development of a suitable three dimensional (3D) culture system for anticancer drug development remains an unmet need. Despite progress, a simple, rapid, scalable and inexpensive 3D-tumor model that recapitulates in vivo tumorigenesis is lacking. Herein, we report on the development and characterization of a 3D nanofibrous scaffold produced by electrospinning a mixture of poly(lactic-co-glycolic acid) (PLGA) and a block copolymer of polylactic acid (PLA) and mono-methoxypolyethylene glycol (mPEG) designated as 3P. Cancer cells cultured on the 3P scaffold formed tight irregular aggregates similar to in vivo tumors, referred to as tumoroids that depended on the topography and net charge of the scaffold. 3P scaffolds induced tumor cells to undergo the epithelial-to-mesenchymal transition (EMT) as demonstrated by up-regulation of vimentin and loss of E-cadherin expression. 3P tumoroids showed higher resistance to anticancer drugs than the same tumor cells grown as monolayers. Inhibition of ERK and PI3K signal pathways prevented EMT and reduced tumoroid formation, diameter and number. Fine needle aspirates, collected from tumor cells implanted in mice when cultured on 3P scaffolds formed tumoroids, but showed decreased sensitivity to anticancer drugs, compared to tumoroids formed by direct seeding. These results show that 3P scaffolds provide an excellent platform for producing tumoroids from tumor cell lines and from biopsies and that the platform can be used to culture patient biopsies, test for anticancer compounds and tailor a personalized cancer treatment.

The receptor for atrial natriuretic peptide (ANP), natriuretic peptide receptor A (NPRA), is expressed in cancer cells, and natriuretic peptides have been implicated in cancers. However, the direct role of NPRA signaling in tumorigenesis remains elusive. Here, we report that NPRA expression and signaling is important for tumor growth. NPRA-deficient mice showed significantly reduced antigen-induced pulmonary inflammation. NPRA deficiency also substantially protected C57BL/6 mice from lung, skin, and ovarian cancers. Furthermore, a nanoparticle-formulated interfering RNA for NPRA attenuated B16 melanoma tumors in mice. Ectopic expression of a plasmid encoding NP73-102, the NH 2 -terminal peptide of the ANP prohormone, which down-regulates NPRA expression, also suppressed lung metastasis of A549 cells in nude mice and tumorigenesis of Line 1 cells in immunocompetent BALB/c mice. The antitumor activity of NP73-102 was in part attributed to apoptosis of tumor cells. Western blot and immunohistochemistry staining indicated that the transcription factor, nuclear factor-KB, was inactivated, whereas the level of tumor suppressor retinoblastoma protein was upregulated in the lungs of NPRA-deficient mice. Furthermore, expression of vascular endothelial growth factor was downregulated in the lungs of NPRA-deficient mice compared with that in wild-type mice. These results suggest that NPRA is involved in tumor angiogenesis and represents a new target for cancer therapy. [Cancer Res 2008;68(1):249-56]

Respiratory syncytial virus (RSV) nonstructural protein 1(NS1) attenuates type-I interferon (IFN) production during RSV infection; however the precise role of RSV NS1 protein in orchestrating the early host-virus interaction during infection is poorly understood. Since NS1 constitutes the first RSV gene transcribed and the production of IFN depends upon RLR (RIG-I-like receptor) signaling, we reasoned that NS1 may interfere with this signaling. Herein, we report that NS1 is localized to mitochondria and binds to mitochondrial antiviral signaling protein (MAVS). Live-cell imaging of rgRSV-infected A549 human epithelial cells showed that RSV replication and transcription occurs in proximity to mitochondria. NS1 localization to mitochondria was directly visualized by confocal microscopy using a cell-permeable chemical probe for His 6 -NS1. Further, NS1 colocalization with MAVS in A549 cells infected with RSV was shown by confocal laser microscopy and immuno-electron microscopy. NS1 protein is present in the mitochondrial fraction and co-immunoprecipitates with MAVS in total cell lysatesof A549 cells transfected with the plasmid pNS1-Flag. By immunoprecipitation with anti-RIG-I antibody, RSV NS1 was shown to associate with MAVS at an early stage of RSV infection, and to disrupt MAVS interaction with RIG-I (retinoic acid inducible gene) and the downstream IFN antiviral and inflammatory response. Together, these results demonstrate that NS1 binds to MAVS and that this binding inhibits the MAVS-RIG-I interaction required for IFN production.

A major problem associated with therapy is the inability to deliver pharmaceuticals to a specific site of the body without causing nonspecific toxicity. Development of magnetic nanoparticles and techniques for their safe transport and concentration in specific sites in the body would constitute a powerful tool for gene/drug therapy in vivo. Furthermore, drug delivery in vitro could improve further if the drugs were modified with antibodies, proteins or ligands. For in vivo experiments, magnetic nanoparticles were conjugated with plasmid DNA expressing GFP and then coated with chitosan. These particles were injected into mice through tail vein and directed to heart and kidney by means of external magnets of 25 gauss or 2kA –kA/m. These particles were concentrated in the lungs, heart, and kidney of mice and the expression of GFP in these sites were monitored. The expression of GFP in specific locations was visualized by whole-body fluorescent imaging and the concentration of these particles in the designated body locations was confirmed by transmission electron microscopy. In another model system, we used atrial natriuretic peptide (ANP) and Carcino Embryonic Antigen (CEA) antibodies coupled to the chitosan coated magnetic nanoparticles to target cells in vitro. The present work demonstrates that a simple external magnetic field is all that is necessary to target a drug to a specific site inside the body without the need to functionalize the nanoparticles. However, the option to use magnetic targeting with external magnets on functionalized nanoparticles could prove as a more efficient means of drug delivery.

Our studies address questions pertaining to the regulation of D cyclin-cdk4 activity, and the following results were obtained. Conditions that increased the abundance of the D cyclins also increased the abundance of enzymatically active D cyclin-cdk4 complexes in mouse embryo fibroblasts (MEFs) lacking both p27 Kip1 The cyclin-dependent kinases (CDKs) mediate the passage of cells through the cell cycle (13). Two families of proteins regulate CDK activity: the cyclins, which are required for activity, and the CDK inhibitors (CKIs). Two CKIs, p27Kip1 and p21Cip1 , associate with complexes containing cyclins D, E, and A and their CDK partners. The D cyclins (D1, D2, and D3) increase in abundance and combine with cdk4 or cdk6 in midto late G 1 , and the resultant complexes phosphorylate the retinoblastoma protein (Rb) and sequester p27Kip1 and p21Cip1 . Sequestration of p27 Kip1 and p21 Cip1 prevents their interaction with, and the consequent inactivation of, cyclin E-cdk2 and cyclin A-cdk2. When active, these complexes further phosphorylate Rb and elicit additional events required for the initiation and execution of S phase.Although p27 Kip1 and p21 Cip1 clearly inhibit cdk2 activity, their effects on cdk4 activity are unresolved. Some studies suggest that p27Kip1 and p21 Cip1 function as obligate assembly factors for D cyclin-cdk4 complexes (4) and that D cyclin-cdk4 complexes containing a single p27Kip1 or p21 Cip1 are active (2, 9, 19). Other studies argue that D cyclin-cdk4 complexes containing p27Kip1 or p21 Cip1 are always inactive. For example, we found that antibody to p27Kip1 or p21 Cip1 coprecipitated D cyclin-cdk4 complexes from extracts of growing fibroblasts but did not remove cdk4 activity (1). Moreover, as reported by us and others, p27Kip1 inhibited cdk4 activity in vitro over a wide range of concentrations (1, 9). We suggest that D cyclin-cdk4 complexes fulfill their enzymatic and sequestration obligations by devoting different portions of the D cyclin-cdk4 pool to each function (1). Inhibitory effects of p27Kip1 and p21 Cip1 on cdk4 activity indicate that these CKIs cannot be required for D cyclin-cdk4 complex formation. Consistent with this premise, we found that D cyclin-cdk4 complexes were present in mouse embryo fibroblasts (MEFs) lacking both p27Kip1 and p21 Cip1 (p27/ p21 Ϫ/Ϫ ), although in smaller amounts than in wild-type MEFs (1). We suggest that the low abundance of D cyclin-cdk4 complexes in p27/p21 Ϫ/Ϫ MEFs reflects the inherent instability of binary D cyclin-cdk4 complexes (9) rather than the need for p27 Kip1 or p21 Cip1 for complex assembly. As described in a previous report (1), most of the D cyclincdk4 complexes in asynchronously cycling wild-type MEFs contain p27Kip1 or p21 Cip1 , whereas the remaining complexes, although almost undetectable, account for all of the D cyclinassociated activity. Thus, in both wild-type and p27/p21 Ϫ/Ϫ MEFs, mechanisms limit the extent and duration of D cyclincdk4 activation. In the presence of p27Kip1 and p21 Cip1 , inactive ternary complexes pr...

Ashwagandha (Withania Somnifera, WS), belonging to the family Solanaceae, is an Ayurvedic herb known worldwide for its numerous beneficial health activities since ancient times. This medicinal plant provides benefits against many human illnesses such as epilepsy, depression, arthritis, diabetes, and palliative effects such as analgesic, rejuvenating, regenerating, and growth-promoting effects. Several clinical trials of the different parts of the herb have demonstrated safety in patients suffering from these diseases. In the last two decades, an active component of Withaferin A (WFA) has shown tremendous cytotoxic activity suggesting its potential as an anti-carcinogenic agent in treatment of several cancers. In spite of enormous progress, a thorough elaboration of the proposed mechanism and mode of action is absent. Herein, we provide a comprehensive review of the properties of WS extracts (WSE) containing complex mixtures of diverse components including WFA, which have shown inhibitory properties against many cancers, (breast, colon, prostate, colon, ovarian, lung, brain), along with their mechanism of actions and pathways involved.