Anti-inflammatory immunotherapy for multiple sclerosis/experimental autoimmune encephalomyelitis (EAE) disease

Multiple sclerosis (MS) and its animal model, experimental autoimmune encephalomyelitis (EAE), are inflammatory diseases of the central nervous system (CNS) characterized by localized areas with demyelination. Disease is believed to be an autoimmune disorder mediated by activated immune cells such as T- and B-lymphocytes and macrophages/microglia. Lymphocytes are primed in the peripheral tissues by antigens, and clonally expanded cells infiltrate the CNS. They produce large amounts of inflammatory cytokines, nitric oxide (NO) that lead to demyelination and axonal degeneration. Although several studies have shown that oligodendrocytes (OLGs), the myelin-forming glial cells in the CNS, are sensitive to cell death stimuli, such as cytotoxic cytokines, anti-myelin antibodies, NO, and oxidative stress, in vitro, the mechanisms underlying injury to the OLGs in MS/EAE remain unclear. The central role of glutamate receptors in mediating excitotoxic neuronal death in stroke, epilepsy, trauma and MS has been well established. Glutamate is the major excitatory amino acid transmitter within the CNS and it's signaling is mediated by a number of postsynaptic ionotropic and metabotropic receptors. Inflammation can be blocked with anti-cell adhesion molecules MAb, simultaneously protected oligodendrocytes and neurons against glutamate-mediated damage with the AMPA/kainate antagonist NBQX, and the NMDA receptor antagonist GPE, could thus be effective therapies for multiple sclerosis.

Bioassay detects soluble MAdCAM-1 in body fluids

Mucosal addressin cell adhesion molecule (MAdCAM-1) is a key player in mediating the infiltration of leucocytes into chronically inflamed tissues. Five anti-MAdCAM-1 monoclonal antibodies (mAb), designated 17F5, 201F7, 314G8, 377D10 and 355G8, were generated by fusion of P3 × 63Ag8.653 myeloma cells with spleen cells from BALB/c mice immunized with recombinant human MAdCAM-1-Fc. The latter four mAb recognize the ligand-binding first Ig domain, and block T -cell adhesion to MAdCAM-1. The non-blocking mAb 17F5 recognizes the mucin domain. Extensive analysis of a large panel of paraffin-embedded human tissues revealed that the 314G8 mAb detected MAdCAM-1 on venules in the spleen and small intestine. MAdCAM-1 was strongly expressed in the synovium of osteoarthritis patients, predominantly on the endothelial lining of blood vessels, but also within the vessel lumen. An ELISA, based on mAb 377D10 and 355G8, was developed to determine whether soluble MAdCAM-1 was present in body fluids, and to measure the levels present. The assay detected soluble MAdCAM-1 in the serum and urine of healthy donors, at levels similar to those of soluble forms of the related CAM, ICAM-1 and VCAM-1. The anti-MAdCAM-1 antibodies and assay developed here may be useful therapeutically in the treatment of inflammation in humans. Similarly, they may be useful diagnostically to monitor the presence and levels of MAdCAM-1.

In vitro spheroids and metastatic epithelial ovarian cancer

This thesis investigated the role of cellular aggregation in the spread of epithelial ovarian cancer. Cell aggregation was studied in vitro in order to identify markers of disease progression and cell-cell adhesion. Proteomics was then used to identify additional proteins associated with cell aggregation and survival.

Biomimetic modification of porous TiNbZr alloy scaffold for bone tissue engineering

Porous titanium (Ti) and Ti alloys are important scaffold materials for bone tissue engineering. In the present study, a new type of porous Ti alloy scaffold with biocompatible alloying elements, that is, niobium (Nb) and zirconium (Zr), was prepared by a space-holder sintering method. This porous TiNbZr scaffold with a porosity of 69% exhibits a mechanical strength of 67MPa and an elastic modulus of 3.9GPa, resembling the mechanical properties of cortical bone. To improve the osteoconductivity, a calcium phosphate (Ca/P) coating was applied to the surface of the scaffold using a biomimetic method. The biocompatibility of the porous TiNbZr alloy scaffold before and after the biomimetic modification was assessed using the SaOS2 osteoblast–like cells. Cell culture results indicated that the porous TiNbZr scaffold is more favorable for cell adhesion and proliferation than its solid counterpart. By applying a Ca/P coating, the cell proliferation rate on the Ca/P-coated scaffold was significantly improved. The results suggest that high-strength porous TiNbZr scaffolds with an appropriate osteoconductive coating could be potentially used for bone tissue engineering application.

Cancer targeted nanoparticles specifically induce apoptosis in cancer cells and spare normal cells

Curing cancer is the greatest challenge for modern medicine and finding ways to minimize the adverse effects caused by chemotherapeutic agents is of importance in improving patient’s physical conditions. Traditionally, chemotherapy can induce various adverse effects, and these effects are mostly caused by the non-target specific properties of the chemotherapeutic compounds. Recently, the use of nanoparticles has been found to be capable of minimizing these drug-induced adverse effects in animals and in patients during cancer treatment. The use of nanoparticles allows various chemotherapeutic drugs to be targeted to cancer cells with lower dosages. In addition to this, the use of nanoparticles also allows various drugs to be administered to the subjects by an oral route. Here, locked nucleic acid (LNA)-modified epithelial cell adhesion molecules (EpCAM), aptamers (RNA nucleotide), and nucleolin (DNA nucleotide) aptamers have been developed and conjugated on anti-cancer drug-loaded nanocarriers for specific delivery to cancer cells and spare normal cells. Significant amounts of the drug loaded nanocarriers (92 ± 6 %) were found to distribute to the cancer cells at the tumour site and more interestingly, normal cells were unaffected in vitro and in vivo. In this review, the benefits of using nanoparticle-coated drugs in various cancer treatments are discussed. Various nanoparticles that have been tried in improving the target specificity and potency of chemotherapeutic compounds are also described.

Role of position 627 of PB2 and the multibasic cleavage site of the hemagglutinin in the virulence of H5N1 avian influenza virus in chickens and ducks

Highly pathogenic H5N1 avian influenza viruses have caused major disease outbreaks in domestic and free-living birds with transmission to humans resulting in 59% mortality amongst 564 cases. The mutation of the amino acid at position 627 of the viral polymerase basic-2 protein (PB2) from glutamic acid (E) in avian isolates to lysine (K) in human isolates is frequently found, but it is not known if this change affects the fitness and pathogenicity of the virus in birds. We show here that horizontal transmission of A/Vietnam/1203/2004 H5N1 (VN/1203) virus in chickens and ducks was not affected by the change of K to E at PB2-627. All chickens died between 21 to 48 hours post infection (pi), while 70% of the ducks survived infection. Virus replication was detected in chickens within 12 hours pi and reached peak titers in spleen, lung and brain between 18 to 24 hours for both viruses. Viral antigen in chickens was predominantly in the endothelium, while in ducks it was present in multiple cell types, including neurons, myocardium, skeletal muscle and connective tissues. Virus replicated to a high titer in chicken thrombocytes and caused upregulation of TLR3 and several cell adhesion molecules, which may explain the rapid virus dissemination and location of viral antigen in endothelium. Virus replication in ducks reached peak values between 2 and 4 days pi in spleen, lung and brain tissues and in contrast to infection in chickens, thrombocytes were not involved. In addition, infection of chickens with low pathogenic VN/1203 caused neuropathology, with E at position PB2-627 causing significantly higher infection rates than K, indicating that it enhances virulence in chickens.

Emerging engineered magnetic nanoparticulate probes for molecular MRI of atherosclerosis : how far have we come?

Atherosclerosis is a chronic, progressive, immunoinflammatory disease of the large and medium-sized arteries, and a major cause of cardiovascular diseases. Atherosclerosis often progresses silently for decades until the occurrence of a major catastrophic clinical event such as myocardial infarction, cardiac arrest and stroke. The main challenge in the diagnosis and management of atherosclerosis is to develop a safe, noninvasive technique that is accurate and reproducible, which can detect the biologically active high-risk vulnerable plaques (with ongoing active inflammation, angiogenesis and apoptosis) before the occurrence of an acute clinical event. This Journal Article reviews the events involved in the pathogenesis of atherosclerosis in light of recently advanced understanding of the molecular pathogenesis of the disease. Next, we elaborate on the interesting developments in molecular MRI, by describing the recently engineered magnetic nanoparticulate probes targeting clinically promising molecular and cellular players/processes, involved in early atherosclerotic lesion formation to plaque rupture and erosion.

Human immunodeficiency virus type 1 protease regulation of tat activity is essential for efficient reverse transcription and replication

The human immunodeficiency virus type 1 (HIV-1) Tat protein enhances reverse transcription, but it is not known whether Tat acts directly on the reverse transcription complex or through indirect mechanisms. Since processing of Tat by HIV protease (PR) might mask its presence and, at least in part, explain this lack of data, we asked whether Tat can be cleaved by PR. We used a rabbit reticulocyte lysate (RRL) system to make Tat and PR. HIV-1 PR is expressed as a Gag-Pol fusion protein, and a PR-inactivated Gag-Pol is also expressed as a control. We showed that Tat is specifically cleaved in the presence of PR, producing a protein of approximately 5 kDa. This result suggested that the cleavage site was located in or near the Tat basic domain (amino acids 49 to 57), which we have previously shown to be important in reverse transcription. We created a panel of alanine-scanning mutations from amino acids 45 to 54 in Tat and evaluated functional parameters, including transactivation, reverse transcription, and cleavage by HIV-1 PR. We showed that amino acids 49 to 52 (RKKR) are absolutely required for Tat function in reverse transcription, that mutation of this domain blocks cleavage by HIV-1 PR, and that other pairwise mutations in this region modulate reverse transcription and proteolysis in strikingly similar degrees. Mutation of Tat Y47G48 to AA also down-regulated Tat-stimulated reverse transcription but had little effect on transactivation or proteolysis by HIV PR, suggesting that Y47 is critical for reverse transcription. We altered the tat gene of the laboratory strain NL4-3 to Y47D and Y47N so that overlapping reading frames were not affected and showed that Y47D greatly diminished virus replication and conveyed a reverse transcription defect. We hypothesize that a novel, cleaved form of Tat is present in the virion and that it requires Y47 for its role in support of efficient reverse transcription.

One step multifunctional micropatterning of surfaces using asymmetric glow discharge plasma polymerization

Micropatterning of surfaces with varying chemical, physical and topographical properties usually requires a number of fabrication steps. Herein, we describe a micropatterning technique based on plasma enhanced chemical vapour deposition (PECVD) that deposits both protein resistant and protein repellent surface chemistries in a single step. The resulting multifunctional, selective surface chemistries are capable of spatially controlled protein adhesion, geometric confinement of cells and the site specific confinement of enzyme mediated peptide self-assembly.

Role of the EpCAM (CD326) in prostate cancer metastasis and progression

Despite significant advances in surgery, radiotherapy and chemotherapy to treat prostate cancer (CaP), many patients die of secondary disease (metastases). Current therapeutic approaches are limited, and there is no cure for metastatic castration-resistant prostate cancer (CRPC). Epithelial cell adhesion molecule (EpCAM, also known as CD326) is a transmembrane glycoprotein that is highly expressed in rapidly proliferating carcinomas and plays an important role in the prevention of cell–cell adhesion, cell signalling, migration, proliferation and differentiation. Stably and highly expressed EpCAM has been found in primary CaP tissues, effusions and CaP metastases, making it an ideal candidate of tumour-associated antigen to detect metastasis of CaP cells in the circulation as well as a promising therapeutic target to control metastatic CRPC disease. In this review, we discuss the implications of the newly identified roles of EpCAM in terms of its diagnostic and metastatic relevance to CaP. We also summarize EpCAM expression in human CaP and EpCAM-mediated signalling pathways in cancer metastasis. Finally, emerging and innovative approaches to the management of the disease and expanding potential therapeutic applications of EpCAM for targeted strategies in future CaP therapy will be explored.

Granulocyte colony-stimulating factor receptor signalling via Janus kinase 2/signal transducer and activator of transcription 3 in ovarian cancer

Ovarian cancer remains a major cause of cancer mortality in women, with only limited understanding of disease aetiology at the molecular level. Granulocyte colony-stimulating factor (G-CSF) is a key regulator of both normal and emergency haematopoiesis, and is used clinically to aid haematopoietic recovery following ablative therapies for a variety of solid tumours including ovarian cancer.

Metabolic remodelling in obesity and type 2 diabetes: pathological or protective mechanisms in response to nutrient excess?

Altered metabolism in tissues such as the liver, skeletal muscle and adipose tissue is observed in metabolic diseases characterized by nutrient excess and energy imbalance, such as obesity and type 2 diabetes. These alterations in metabolism can include resistance to the hormone insulin, lipid accumulation, mitochondrial dysfunction and transcriptional remodelling of major metabolic pathways. The underlying assumption has been that these same alterations in metabolism are fundamental to the pathogenesis of metabolic diseases. An alternative view is that these alterations in metabolism occur to protect cell and tissue viability in the face of constant positive energy balance. This speculative review presents evidence that many of the metabolic adaptations that occur in metabolic diseases characterized by nutrient excess can be viewed as protective in nature, rather than pathogenic per se for disease progression. Finally, we also briefly discuss the usefulness and potential pitfalls of therapeutic approaches that attempt to correct these same metabolic defects when energy balance is not altered, and the potential links between metabolic survival responses and other chronic diseases such as cancer.

Nucleic acid aptamer-guided cancer therapeutics and diagnostics: the next generation of cancer medicine

Conventional anticancer therapies, such as chemo- and/or radio-therapy are often unable to completely eradicate cancers due to abnormal tumor microenvironment, as well as increased drug/radiation resistance. More effective therapeutic strategies for overcoming these obstacles are urgently in demand. Aptamers, as chemical antibodies that bind to targets with high affinity and specificity, are a promising new and novel agent for both cancer diagnostic and therapeutic applications. Aptamer-based cancer cell targeting facilitates the development of active targeting in which aptamer-mediated drug delivery could provide promising anticancer outcomes. This review is to update the current progress of aptamer-based cancer diagnosis and aptamer-mediated active targeting for cancer therapy in vivo, exploring the potential of this novel form of targeted cancer therapy.

MicroRNA pathways : an emerging role in identification of therapeutic strategies

For years researchers have exerted every effort to improve the influential roles of microRNA (miRNA) in regulating genes that direct mammalian cell development and function. In spite of numerous advancements, many facets of miRNA generation remain unresolved due to the perplexing regulatory networks. The biogenesis of miRNA, eminently endures as a mystery as no universal pathway defines or explicates the variegation in the rise of miRNAs. Early evidence in biogenesis ignited specific steps of being omitted or replaced that eventuate in the individual miRNAs of different mechanisms. Understanding the basic foundation concerning how miRNAs are generated and function will help with diagnostic tools and therapeutic strategies. This review encompasses the canonical and the non-canonical pathways involved in miRNA biogenesis, while elucidating how miRNAs regulate genes at the nuclear level and also the mechanism that lies behind circulating miRNAs.

Lubricin: a versatile, biological anti-adhesive with properties comparable to polyethylene glycol

Lubricin is a glycoprotein found in articular joints which has been recognized as being an important biological boundary lubricant molecule. Besides providing lubrication, we demonstrate, using a quartz crystal microbalance, that lubricin also exhibits anti-adhesive properties and is highly effective at preventing the non-specific adsorption of representative globular proteins and constituents of blood plasma. This impressive anti-adhesive property, combined with lubricin's ability to readily self-assemble to form dense, highly stable telechelic polymer brush layers on virtually any substrates, and its innate biocompatibility, makes it an attractive candidate for anti-adhesive and anti-fouling coatings. We show that coatings of lubricin protein are as effective as, or better than, self-assembled monolayers of polyethylene glycol over a wide range of pH and that this provides a simple, versatile, highly stable, and highly effective method of controlling unwanted adhesion to surfaces.