Synthetic Glycolipids as Molecular Vaccine Adjuvants: Mechanism of Action in Human Cells and In Vivo Activity.

Modern adjuvants for vaccine formulations are immunostimulating agents whose action is based on the activation of pattern recognition receptors (PRRs) by well-defined ligands to boost innate and adaptive immune responses. Monophosphoryl lipid A (MPLA), a detoxified analogue of lipid A, is a clinically approved adjuvant that stimulates toll-like receptor 4 (TLR4). The synthesis of MPLA poses manufacturing and quality assessment challenges.

Synthetic glycolipid-based TLR4 antagonists negatively regulate TRIF-dependent TLR4 signalling in human macrophages.

TLRs, including TLR4, play a crucial role in inflammatory-based diseases, and TLR4 has been identified as a therapeutic target for pharmacological intervention. In previous studies, we investigated the potential of FP7, a novel synthetic glycolipid active as a TLR4 antagonist, to inhibit haematopoietic and non-haematopoietic MyD88-dependent TLR4 pro-inflammatory signalling. The main aim of this study was to investigate the action of FP7 and its derivative FP12 on MyD88-independent TLR4 signalling in THP-1 derived macrophages.

The synthetic glycolipid-based TLR4 antagonist FP7 negatively regulates in vitro and in vivo haematopoietic and non-haematopoietic vascular TLR4 signalling.

TLRs, including TLR4, have been shown to play a crucial role in cardiovascular inflammatory-based diseases. The main goal of this study was to determine the potential of FP7, a synthetic glycolipid active as a TLR4 antagonist, to modulate haematopoietic and non-haematopoietic vascular TLR4 pro-inflammatory signalling. HUVEC, human THP-1 monocytes, THP-1-derived macrophages, mouse RAW-264.

Structure-Activity Relationship in Monosaccharide-Based Toll-Like Receptor 4 (TLR4) Antagonists.

The structure-activity relationship was investigated in a series of synthetic TLR4 antagonists formed by a glucosamine core linked to two phosphate esters and two linear carbon chains. Molecular modeling showed that the compounds with 10, 12, and 14 carbons chains are associated with higher stabilization of the MD-2/TLR4 antagonist conformation than in the case of the C16 variant. Binding experiments with human MD-2 showed that the C12 and C14 variants have higher affinity than C10, while the C16 variant did not interact with the protein.

Increased Expression of Lamin A/C Correlate with Regions of High Wall Stress in Abdominal Aortic Aneurysms.

Background: Since aortic diameter is the most -significant risk factor for rupture, we sought to identify stress-dependent changes in gene expression to illuminate novel molecular processes in aneurysm rupture.

Materials And Methods: We constructed finite element maps of abdominal computerized tomography scans (CTs) of seven abdominal aortic aneurysm (AAA) patients to map wall stress. Paired biopsies from high- and low-stress areas were collected at surgery using vascular landmarks as coordinates.

A novel small molecule TLR4 antagonist (IAXO-102) negatively regulates non-hematopoietic toll like receptor 4 signalling and inhibits aortic aneurysms development.

Objectives: The toll-like receptors (TLRs), including TLR4, have been shown to play a crucial role in vascular inflammatory diseases, such as atherosclerosis and aneurysm. The main goal of this study was to determine the potential of IAXO-102 (Innaxon, Tewkesbury), a novel small molecule TLR4 antagonist, to modulate non-hematopoietic TLR4 proinflammatory signalling and inhibit experimental abdominal aortic aneurysm (AAA) development.

Methods: Human umbilical vein endothelial cells (HUVEC) and Angiotensin II-induced experimental AAA development were our in vitro and in vivo models respectively.

Specific inhibition of c-Jun N-terminal kinase delays preterm labour and reduces mortality.

Preterm labour (PTL) is commonly associated with infection and/or inflammation. Lipopolysaccharide (LPS) from different bacteria can be used to independently or mutually activate Jun N-terminal kinase (JNK)/AP1- or NF-κB-driven inflammatory pathways that lead to PTL. Previous studies using Salmonella abortus LPS, which activates both JNK/AP-1 and NF-κB, showed that selective inhibition of NF-κB delays labour and improves pup outcome.

Pioglitazone Identifies a New Target for Aneurysm Treatment: Role of Egr1 in an Experimental Murine Model of Aortic Aneurysm.

Peroxisome proliferator-activated receptor x03B3; agonists have been shown to inhibit angiotensin II (AngII)-induced experimental abdominal aortic aneurysms. Macrophage infiltration to the vascular wall is an early event in this pathology, and therefore we explored the effects of the peroxisome proliferator-activated receptor x03B3; agonist pioglitazone on AngII-treated macrophages. Using microarray-based expression profiling of phorbol ester-stimulated THP-1 cells, we found that a number of aneurysm-related gene changes effected by AngII were modulated following the addition of pioglitazone.

Differential role of apoptosis and autophagy associated with anticancer effect of lupulone (hop β-acid) derivatives on prostate cancer cells.

Lupulone, a β-acid derived from hop extracts has been shown to exhibit cytotoxic activity against cancer cells. In this study we investigated the functional role of different modes of cell death that mediate anticancer effect of lupulone derivatives in prostate cancer cells. ELISA, immunoblotting and siRNA approaches were utilised to study cell death, expression of proteins of interest and their functional activities.

An investigation into the anticancer effects and mechanism of action of hop β-acid lupulone and its natural and synthetic derivatives in prostate cancer cells.

Lupulone, a β-acid derived from hop extracts has been shown to exhibit antibacterial and anticancer activity. In this study we investigated the anticancer potency of lupulone and its novel derivatives and their mechanism of action on prostate cancer cells. Cell viability was determined using the MTT assay, and the ELISA approach was used to investigate induction of apoptosis.

Elevation of plasma high-density lipoproteins inhibits development of experimental abdominal aortic aneurysms.

Objective: Patients with abdominal aortic aneurysms have lower concentrations of high-density lipoproteins (HDLs), leading us to investigate whether increasing plasma HDLs could influence aneurysm formation.

Methods And Results: Using the angiotensin II-induced hypercholesterolemic and the CaCl(2)-induced normocholesterolemic mouse model of AAA, we investigated the hypothesis that elevation of HDLs inhibits AAA. HDLs elevated before or at the time of AAA induction reduced AAA formation in both models but had no effect on early ruptures.

Rosiglitazone negatively regulates c-Jun N-terminal kinase and toll-like receptor 4 proinflammatory signalling during initiation of experimental aortic aneurysms.

Objective: Development and rupture of aortic aneurysms (AA) is a complex process involving inflammation, cell death, tissue and matrix remodelling. The thiazolidinediones (TZDs) including Rosiglitazone (RGZ) are a family of drugs which act as agonists of the nuclear peroxisome proliferator-activated receptors and have a broad spectrum of effects on a number of biological processes in the cardiovascular system. In our previous study we have demonstrated that RGZ has a marked effect on both aneurysm rupture and development, however, the precise mechanism of this is unknown.

Diabetes as a negative risk factor for abdominal aortic aneurysm - does the disease aetiology or the treatment provide the mechanism of protection?

There is strong epidemiological evidence that patients with diabetes have a lower incidence of abdominal aortic aneurysm. The precise mechanism of this negative association is unknown. Whilst a number of studies have supported the hypothesis that protection is a function of diabetes-mediated changes in the vascular extracellular matrix biology, there is also support for the idea that the treatment regimens used in diabetes may afford protection against AAA.

Urocortin is a novel regulator of osteoclast differentiation and function through inhibition of a canonical transient receptor potential 1-like cation channel.

This study investigated the role of urocortin (UCN), a member of the corticotrophin-releasing factor (CRF) family of peptides, in osteoclast maturation and function. We found that 10(-7) M UCN significantly (P<0.05) suppressed osteoclast differentiation from bone marrow precursor cells in culture and reduced the expression of several osteoclastic markers.

Comparative proteomics reveals a systemic vulnerability in the vasculature of patients with abdominal aortic aneurysms.

Introduction: Abdominal aortic aneurysms (AAA) are associated with inflammation, apoptosis, and matrix degradation. AAA tissue represents the end stage of disease, limiting its utility in identification of factors culpable for initiation of aneurysm development. Recent evidence suggests that AAAs are a local representation of a systemic disease of the vasculature.

Attenuation of proliferation in oligodendrocyte precursor cells by activated microglia.

Activated microglia can influence the survival of neural cells through the release of cytotoxic factors. Here, we investigated the interaction between Toll-like receptor 4 (TLR4)-activated microglia and oligodendrocytes or their precursor cells (OPC). Primary rat or N9 microglial cells were activated by exposure to TLR4-specifc lipopolysaccharide (LPS), resulting in mitogen-activated protein kinase activation, increased CD68 and inducible nitric oxide synthase expression, and release of the proinflammatory cytokines tumor necrosis factor (TNF) and interleukin-6 (IL-6).

Differentiation of human fetal mesenchymal stem cells into cells with an oligodendrocyte phenotype.

The potential of mesenchymal stem cells (MSC) to differentiate into neural lineages has raised the possibility of autologous cell transplantation as a therapy for neurodegenerative diseases. We have identified a population of circulating human fetal mesenchymal stem cells (hfMSC) that are highly proliferative and can readily differentiate into mesodermal lineages such as bone, cartilage, fat and muscle. Here, we demonstrate for the first time that primary hfMSC can differentiate into cells with an oligodendrocyte phenotype both in vitro and in vivo.

The cyclopentenone 15-deoxy-delta 12,14-prostaglandin J(2) delays lipopolysaccharide-induced preterm delivery and reduces mortality in the newborn mouse.

Intrauterine infection is a common trigger for preterm birth and is also a risk factor for the subsequent development of neurodevelopmental abnormalities in the neonate. Bacterial lipopolysaccharide (LPS) binds to toll-like receptor-4 (TLR-4) to activate proinflammatory signaling pathways, which are implicated in both preterm delivery and antenatal brain injury. The transcription factor nuclear factor-kappaB (NF-kappaB) is a key player in the orchestration of the inflammatory response and has a central role in parturition.

Deletion of the c-Jun N-terminal kinase 3 gene protects neonatal mice against cerebral hypoxic-ischaemic injury.

c-Jun N-terminal kinase 3 (JNK3) is a member of the stress-activated group of mitogen-activated protein kinases. c-Jun N-terminal kinase 3 is a potent mediator of apoptosis and the use of JNK inhibitors or jnk3 gene deletion each protect against brain injury in adults. However, little is known about the role of JNK3 or its mechanism of action in neonatal brain injury.

Differential expression of FOXO1 and FOXO3a confers resistance to oxidative cell death upon endometrial decidualization.

The integrity of the feto-maternal interface is critical for survival of the conceptus. This interface, consisting of the maternal decidua and the invading placental trophoblast, is exposed to profound changes in oxygen tension during pregnancy. We demonstrate that human endometrial stromal cells become extraordinarily resistant to oxidative stress-induced apoptosis upon decidualization in response to cAMP and progesterone signaling.