Pharmacological characterisation of GSK3335103, an oral αvß6 integrin small molecule RGD-mimetic inhibitor for the treatment of fibrotic disease.

Fibrosis is the formation of scar tissue due to injury or long-term inflammation and is a leading cause of morbidity and mortality. Activation of the pro-fibrotic cytokine transforming growth factor-ß (TGFß) via the alpha-V beta-6 (αvß6) integrin has been identified as playing a key role in the development of fibrosis. Therefore, a drug discovery programme to identify an orally bioavailable small molecule αvß6 arginyl-glycinyl-aspartic acid (RGD)-mimetic was initiated. As part of a medicinal chemistry programme GSK3335103 was identified and profiled in a range of pre-clinical in vitro and in vivo systems. GSK3335103 was shown to bind to the αvß6 with high affinity and demonstrated fast binding kinetics. In primary human lung epithelial cells, GSK3335103-induced concentration- and time-dependent internalisation of αvß6 with a rapid return of integrin to the cell surface observed after washout. Following sustained engagement of the αvß6 integrin in vitro, lysosomal degradation was induced by GSK3335103. GSK3335103 was shown to engage with the αvß6 integrin and inhibit the activation of TGFß in both ex vivo IPF tissue and in a murine model of bleomycin-induced lung fibrosis, as measured by αvß6 engagement, TGFß signalling and collagen deposition, with a prolonged duration of action observed in vivo. In summary, GSK3335103 is a potent αvß6 inhibitor that attenuates TGFß signalling in vitro and in vivo with a well-defined pharmacokinetic/pharmacodynamic relationship. This translates to a significant reduction of collagen deposition in vivo and therefore GSK3335103 represents a potential novel oral therapy for fibrotic disorders.

Strategies to manage hepatitis C virus (HCV) infection disease burden - volume 2.

The hepatitis C virus (HCV) epidemic was forecasted through 2030 for 15 countries, and the relative impact of two scenarios was considered: (i) increased treatment efficacy while holding the treated population constant and (ii) increased treatment efficacy and increased annual treated population. Increasing levels of diagnosis and treatment, in combination with improved treatment efficacy, were critical for achieving substantial reductions in disease burden. In most countries, the annual treated population had to increase several fold to achieve the largest reductions in HCV-related morbidity and mortality. This suggests that increased capacity for screening and treatment will be critical in many countries. Birth cohort screening is a helpful tool for maximizing resources. In most of the studied countries, the majority of patients were born between 1945 and 1985.

The present and future disease burden of hepatitis C virus (HCV) infections with today's treatment paradigm - volume 2.

Morbidity and mortality attributable to chronic hepatitis C virus (HCV) infection are increasing in many countries as the infected population ages. Models were developed for 15 countries to quantify and characterize the viremic population, as well as estimate the number of new infections and HCV related deaths from 2013 to 2030. Expert consensus was used to determine current treatment levels and outcomes in each country. In most countries, viremic prevalence has already peaked. In every country studied, prevalence begins to decline before 2030, when current treatment levels were held constant. In contrast, cases of advanced liver disease and liver related deaths will continue to increase through 2030 in most countries. The current treatment paradigm is inadequate if large reductions in HCV related morbidity and mortality are to be achieved.

Historical epidemiology of hepatitis C virus (HCV) in selected countries.

Chronic infection with hepatitis C virus (HCV) is a leading indicator for liver disease. New treatment options are becoming available, and there is a need to characterize the epidemiology and disease burden of HCV. Data for prevalence, viremia, genotype, diagnosis and treatment were obtained through literature searches and expert consensus for 16 countries. For some countries, data from centralized registries were used to estimate diagnosis and treatment rates. Data for the number of liver transplants and the proportion attributable to HCV were obtained from centralized databases. Viremic prevalence estimates varied widely between countries, ranging from 0.3% in Austria, England and Germany to 8.5% in Egypt. The largest viremic populations were in Egypt, with 6,358,000 cases in 2008 and Brazil with 2,106,000 cases in 2007. The age distribution of cases differed between countries. In most countries, prevalence rates were higher among males, reflecting higher rates of injection drug use. Diagnosis, treatment and transplant levels also differed considerably between countries. Reliable estimates characterizing HCV-infected populations are critical for addressing HCV-related morbidity and mortality. There is a need to quantify the burden of chronic HCV infection at the national level.

The present and future disease burden of hepatitis C virus (HCV) infection with today's treatment paradigm.

The disease burden of hepatitis C virus (HCV) is expected to increase as the infected population ages. A modelling approach was used to estimate the total number of viremic infections, diagnosed, treated and new infections in 2013. In addition, the model was used to estimate the change in the total number of HCV infections, the disease progression and mortality in 2013-2030. Finally, expert panel consensus was used to capture current treatment practices in each country. Using today's treatment paradigm, the total number of HCV infections is projected to decline or remain flat in all countries studied. However, in the same time period, the number of individuals with late-stage liver disease is projected to increase. This study concluded that the current treatment rate and efficacy are not sufficient to manage the disease burden of HCV. Thus, alternative strategies are required to keep the number of HCV individuals with advanced liver disease and liver-related deaths from increasing.

Ultrastructural and behavioural changes precede amyloid deposition in a transgenic model of Alzheimer's disease.

We describe the thorough characterisation of a new transgenic mouse line overexpressing the 695-amino acid isoform of human amyloid precursor protein harbouring the Swedish double familial Alzheimer's disease mutation. This line, referred to as TAS10, exhibits neuropathological features and cognitive deficits that are closely correlated to the accumulation of Abeta in their brain and that are reminiscent of those observed in AD. Data on the TAS10 line are presented at five time points: 2, 6, 12, 18 and 24 months in a longitudinal study. The TAS10 line is characterised by the following changes: i) significant age-related increases in the levels of total and individual species (1-40, 1-42) of beta-amyloid in the brains of transgenics compared with non-transgenic littermates; ii) transgenic mice showed pronounced spatial learning deficits in the Morris water maze at 6 months and working memory deficits by 12 months; iii) amyloid plaque and associated pathologies were observed by the 12-month time point and the burden increased substantially, particularly in the cortex, by 18 months; iv) electron microscopy of the hippocampus of transgenic mice showed evidence of abnormal ultrastructural features such as dystrophic neurites and lipid deposits that developed from 6 months and increased in number and severity with age. Morphometric studies demonstrate that the synapse to neuron ratio is higher in transgenics than in control mice at 12 months, but this ratio decreases as they age and synapse size increases. Thus, this mouse model exhibits a close correlation of amyloid burden with behavioural deficits and ultrastructural abnormalities and so represents an ideal system to study the mechanisms underlying the impact of amyloid pathology on CNS function.

Dishevelled regulates the metabolism of amyloid precursor protein via protein kinase C/mitogen-activated protein kinase and c-Jun terminal kinase.

Alzheimer's disease (AD) is a disorder of two pathologies: amyloid plaques, the core of which is a peptide derived from the amyloid precursor protein (APP), and neurofibrillary tangles composed of highly phosphorylated tau. Protein kinase C (PKC) is known to increase non-amyloidogenic alpha-secretase cleavage of APP, producing secreted APP (sAPPalpha), and glycogen synthase kinase (GSK)-3beta is known to increase tau phosphorylation. Both PKC and GSK-3beta are components of the wnt signaling cascade. Here we demonstrate that overexpression of another member of this pathway, dishevelled (dvl-1), increases sAPPalpha production. The dishevelled action on APP is mediated via both c-jun terminal kinase (JNK) and protein kinase C (PKC)/mitogen-activated protein (MAP) kinase but not via p38 MAP kinase. These data position dvl-1 upstream of both PKC and JNK, thereby explaining the previously observed dual signaling action of dvl-1. Furthermore, we show that human dvl-1 and wnt-1 also reduce the phosphorylation of tau by GSK-3beta. Therefore, both APP metabolism and tau phosphorylation are potentially linked through wnt signaling.

Mild hypercholesterolemia and premature heart disease: do the national criteria underestimate disease risk?

OBJECTIVES: To determine the frequency of hospital admissions for acute coronary syndrome in young adults and to examine the risk factors that predispose to the development of premature heart disease. BACKGROUND: Significant coronary heart disease (CHD) is considered rare in the young adult. Current guidelines do not recommend treatment of mild cholesterol abnormalities for primary prevention of CHD in the young. METHODS: This is a large case series of 449 adults (< or =50 years) admitted to the hospital with acute coronary syndrome. A history of cardiovascular risk factors and lipid profile were recorded. The presence and extent of CHD were established. RESULTS: Mean patient age was 44 +/- 6 years. Documented CHD was present in 61% of hospital admissions. Multivariate analysis revealed that history of hypercholesterolemia, history of smoking and diabetes were independently associated with premature CHD. The fasting lipid profiles were only borderline to mildly abnormal. Serum total cholesterol, low-density lipoprotein (LDL) and triglyceride levels were not different in cases compared with control subjects. Nearly half (49%) of those with LDL levels of > or =160 mg/dl had only one additional risk factor or none. Despite this, a history of hypercholesterolemia had independent and incremental value on other risk factors for the likelihood of premature CHD. CONCLUSIONS: The magnitude of hospital admissions relating to premature CHD is high. In this population, the presence of borderline or mild hypercholesterolemia has significant effects on the development of premature CHD. These observations have significant implications in the development of guidelines for primary prevention of premature CHD.

Short-term memory for the temporal order of events in monkeys.

Two monkeys (Macaca fascicularis) demonstrated short-term memory for the recency of unpredictable visual events in a probe recognition task. On each trial, from two to five 3-dimensional objects were randomly selected from a pool of 200 and presented sequentially. In the test probe that followed, the subjects saw two objects from the preceding list and chose the one that had appeared earlier. Overall accuracy was 73% correct. Like human judgments of recency, accuracy varied inversely with the lag and directly with the temporal separation of the objects in the probe. The data suggest that monkeys encode information about object order as well as object identity, their mnemonic representation of the ordered list contains information about all of its constituent elements, and recency judgments are made at the time the probe is presented and not before. Monkey processing of temporal order information is in these respects similar to human order memory.

The long-term retention of events in monkey memory.

Nine monkeys (Macaca fascicularis) demonstrated long-term memory for objects in a recognition task based on the non-matching-to-sample (NMTS) paradigm. In this task, the subjects were required to choose a novel object when it was paired with an alternative that had become familiar in previous NMTS training. When the familiar objects had been experienced an average of 3.4 times 4-9 months previously, 5 monkeys made 79% correct choices of the novel object. Three other monkeys exposed to the objects a mean of 12.8 times were 65% accurate at retention intervals of 20 months. A ninth subject achieved an accuracy of 68% after a retention interval of 34 months based on an exposure frequency of 10.6. These levels of performance indicate that in monkey event memory the mnemonic representation of an object is quite durable and a proportion of visual information may last for at least 3 years.

Efferent projections from limbic cortex of the temporal pole to the magnocellular medial dorsal nucleus in the rhesus monkey.

The efferent projection from the rostral cortices of the temporal lobe to the magnocellular division of the medial dorsal nucleus (MDmc) was studied in the rhesus monkey (Macaca mulatta). The temporal pole region contains four architectonically defined cortical divisions. Medially, the allocortex of the temporal limb of the pyriform cortex is annexed to the temporal lobe neocortices at the limen insulae. Two transitional neocortices, the periallocortical and proisocortical divisions, are situated subjacent to the pyriform area. They make up the largest part of the temporal tip and separate the pyriform cortex from the architecturally more progressive isocortical divisions of the pole found laterally at the rostral ends of the superior and inferior temporal gyri. Neuroanatomical tracers were injected into each of the major divisions of the temporal pole cortex, and the injection site locations were characterized cytoarchitectonically as well as geographically. Injections of tritiated amino acids into pyriform allocortex or into the transitional neocortical fields revealed an efferent projection to the magnocellular medial dorsal nucleus. The terminal field was characterized by a mosaic type of organization and contained discrete zones of axonal termination in which bursts of coarse label surrounded neuronal perikarya and their proximal dendrites. A similar projection was also observed when horseradish peroxidase was injected into the transitional cortices. However, perikarya participating in the terminal clusters were not retrogradely labeled. Intracortical injections restricted to lateral polar isocortex did not result in either anterograde or retrograde transport of label to MDmc. These findings demonstrate a nonreciprocal, corticofugal pathway to MDmc that originates in the phylogenetically older districts of the temporal pole. The conduction of limbic sensory information directly from temporal neocortex to the medial thalamus may play a fundamental role in human and primate memory.

Additional factors influencing sensitivity in the tetramethyl benzidine method for horseradish peroxidase neurohistochemistry.

In experiments that use horseradish peroxidase (HRP) and tetramethyl benzidine (TMB) for tracing neural connections, the activity of tissue-bound enzyme as well as the stability of the resultant reaction product are influenced by the duration of storage, the composition of the storage medium, the type of counterstaining and even the details of histological dehydration. Furthermore, the conditions for preserving HRP activity are very different from those necessary for preserving the stability of the tetramethyl benzidine (TMB) reaction product. Thus, tissue-bound HRP activity is stable at a neutral pH, while a much lower pH, around 3.3, is required for preserving the stability of the TMB reaction product. Recent evidence indicates that the stabilization bath in sodium nitroferricyanide that was previously recommended is not necessary. However, gradual dehydration of mounted sections is essential for long-term stability. Excessive counterstaining and excessive dehydration interfere with the detection of reaction product. These considerations are pertinent to experiments using free HRP as well as to those where the enzyme has been conjugated to wheat germ agglutinin.