Use of theragnostic markers to select drugs for phase II/III trials for Alzheimer disease

Cognitive screening in chronic obstructive pulmonary disease: patient's perspectives

Purpose: Cognitive impairment is highly prevalent (61%) in chronic obstructive pulmonary disease (COPD). International guidelines recommend providing self-management education through resource-intensive, pulmonary rehabilitation programs, yet screening for deficits likely to interfere with learning have received insufficient attention. Concerns over cognitive testing as confronting are described by health professionals as a barrier to screening, but with minimal empiric data. This study explored views on cognitive impairment and screening in patients with COPD.Design: Qualitative study, focus groups.Methods: Participants with COPD were recruited from a respiratory service at a regional hospital. Conversations were recorded, transcribed verbatim, and analyzed using thematic analysis.Results: Focus groups were undertaken between February and May 2014. Fifteen patients, with a diagnosis of COPD and mean age of 73, participated. Thematic analysis resulted in four overall themes: (1) limited awareness of the connection between cognitive change and COPD; (2) cognitive change as part of normal ageing; (3) current strategies for self-management activities and cognition functioning; and (4) attitudes to cognitive testing.Conclusions: This study identified that participants were open to discussing issues of cognitive function suggesting that normalizing discussion around cognitive change presents an opportunity to introduce screening within routine assessments. Identifying cognitive impairment provides opportunity to tailor rehabilitation for those at risk of sub-optimal self-management.Implications for RehabilitationChanges in cognition are recognized as a barrier to optimal self-management and rehabilitation efficacy in chronic disease.This study identified that participants were open to discussing issues of cognitive function suggesting that normalizing discussion around cognitive change presents an opportunity to introduce screening within routine assessments.Identifying cognitive impairment provides opportunity to tailor rehabilitation for those at risk of sub-optimal self-management.

Computer-Aided Multi-Target Management of Emergent Alzheimer's Disease

Alzheimer's disease (AD) represents an enormous global health burden in terms of human suffering and economic cost. AD management requires a shift from the prevailing paradigm targeting pathogenesis to design and develop effective drugs with adequate success in clinical trials. Therefore, it is of interest to report a review on amyloid beta (Aβ) effects and other multi-targets including cholinesterase, NFTs, tau protein and TNF associated with brain cell death to be neuro-protective from AD. It should be noted that these molecules have been generated either by target-based or phenotypic methods. Hence, the use of recent advancements in nanomedicine and other natural compounds screening tools as a feasible alternative for circumventing specific liabilities is realized. We review recent developments in the design and identification of neuro-degenerative compounds against AD generated using current advancements in computational multi-target modeling algorithms reflected by theragnosis (combination of diagnostic tests and therapy) concern.

Validation of a Chemiluminescence Immunoassay for Measuring Amyloid-β in Human Blood Plasma

The technical performance of immunological assays and their suitability for the intended use should be carefully validated before implementation in research, clinical studies or routine. We describe here the evaluation of a sandwich electrochemiluminescence immunoassay for measuring total Amyloid-β levels in human blood plasma as an example of a laboratory protocol for a partial "fit for purpose" assay performance validation. We tested two different assay protocols and addressed impact of sample dilution, parallelism, intra- and inter-assay variance, lower limit of quantification, lower limit of detection, and analytical spike recoveries.

NOTCH inhibits osteoblast formation in inflammatory arthritis via noncanonical NF-κB

NOTCH-dependent signaling pathways are critical for normal bone remodeling; however, it is unclear if dysfunctional NOTCH activation contributes to inflammation-mediated bone loss, as observed in rheumatoid arthritis (RA) patients. We performed RNA sequencing and pathway analyses in mesenchymal stem cells (MSCs) isolated from transgenic TNF-expressing mice, a model of RA, to identify pathways responsible for decreased osteoblast differentiation. 53 pathways were dysregulated in MSCs from RA mice, among which expression of genes encoding NOTCH pathway members and members of the noncanonical NF-κB pathway were markedly elevated. Administration of NOTCH inhibitors to RA mice prevented bone loss and osteoblast inhibition, and CFU-fibroblasts from RA mice treated with NOTCH inhibitors formed more new bone in recipient mice with tibial defects. Overexpression of the noncanonical NF-κB subunit p52 and RELB in a murine pluripotent stem cell line increased NOTCH intracellular domain-dependent (NICD-dependent) activation of an RBPjκ reporter and levels of the transcription factor HES1. TNF promoted p52/RELB binding to NICD, which enhanced binding at the RBPjκ site within the Hes1 promoter. Furthermore, MSC-enriched cells from RA patients exhibited elevated levels of HES1, p52, and RELB. Together, these data indicate that persistent NOTCH activation in MSCs contributes to decreased osteoblast differentiation associated with RA and suggest that NOTCH inhibitors could prevent inflammation-mediated bone loss.

Translational paradigms in pharmacology and drug discovery

The translational sciences represent the core element in enabling and utilizing the output from the biomedical sciences and to improving drug discovery metrics by reducing the attrition rate as compounds move from preclinical research to clinical proof of concept. Key to understanding the basis of disease causality and to developing therapeutics is an ability to accurately diagnose the disease and to identify and develop safe and effective therapeutics for its treatment. The former requires validated biomarkers and the latter, qualified targets. Progress has been hampered by semantic issues, specifically those that define the end product, and by scientific issues that include data reliability, an overt reductionistic cultural focus and a lack of hierarchically integrated data gathering and systematic analysis. A necessary framework for these activities is represented by the discipline of pharmacology, efforts and training in which require recognition and revitalization.

Use of biomarkers and imaging to assess pathophysiology, mechanisms of action and target engagement

Multidisciplinary basic research led to an evolving knowledge of the molecular pathogenesis of Alzheimer's disease (AD). These advances have been translated into defined therapeutic concepts and distinct classes of compounds with putative disease-modifying effects that are now being tested in clinical trials. There is a growing consensus that disease-modifying treatments may be most effective when commenced early in the course and progression of AD pathophysiology, before amyloid deposition and neurodegeneration become too widespread. Biological indicators of pathophysiological mechanisms are required to chart and identify AD in the prodromal phase or, preferably, in asymptomatic individuals. Biomarkers are becoming even more important, owing to the challenges in demonstrating efficacy of candidate-drugs that hit pathophysiological targets using clinical and cognitive outcomes in early AD trials with limited duration. Currently, there is emerging consensus that advances in therapeutic strategies for AD that delay predefined milestones or slow the cognitive and disease progression would considerably decrease the expanding global burden of the disease. To effectively test preventive compounds for AD and bring therapy to affected individuals as early as possible there is an urgent need for a concerted collaboration among worldwide academic institutions, industry, and regulatory bodies with the aim of establishing networks for the identification and qualification of multi-modal biological disease markers.

Alzheimer's therapeutics: continued clinical failures question the validity of the amyloid hypothesis-but what lies beyond?

The worldwide incidence of Alzheimer's disease (AD) is increasing with estimates that 115 million individuals will have AD by 2050, creating an unsustainable healthcare challenge due to a lack of effective treatment options highlighted by multiple clinical failures of agents designed to reduce the brain amyloid burden considered synonymous with the disease. The amyloid hypothesis that has been the overarching focus of AD research efforts for more than two decades has been questioned in terms of its causality but has not been unequivocally disproven despite multiple clinical failures, This is due to issues related to the quality of compounds advanced to late stage clinical trials and the lack of validated biomarkers that allow the recruitment of AD patients into trials before they are at a sufficiently advanced stage in the disease where therapeutic intervention is deemed futile. Pursuit of a linear, reductionistic amyloidocentric approach to AD research, which some have compared to a religious faith, has resulted in other, equally plausible but as yet unvalidated AD hypotheses being underfunded leading to a disastrous roadblock in the search for urgently needed AD therapeutics. Genetic evidence supporting amyloid causality in AD is reviewed in the context of the clinical failures, and progress in tau-based and alternative approaches to AD, where an evolving modus operandi in biomedical research fosters excessive optimism and a preoccupation with unproven, and often ephemeral, biomarker/genome-based approaches that override transparency, objectivity and data-driven decision making, resulting in low probability environments where data are subordinate to self propagating hypotheses.

The value of cerebrospinal fluid biomarkers for the differential diagnosis of dementia

SUMMARY The diagnostic markers for Alzheimer’s disease (AD) (β-amyloid1–42, total tau protein and hyperphosphorylated tau) are gradually finding their way into routine clinical practice as an affirmative diagnostic tool, rather than an exclusionary one. Their discriminatory power for the differential diagnosis of dementia is, however, suboptimal and other cerebrospinal fluid biomarkers, especially those that are reflective of the pathology of the non-AD dementia etiologies, could improve the differential dementia diagnosis either by their individual use (diagnostic value) or in combination with the established AD biomarkers (added diagnostic value). Unfortunately, validated biomarkers for non-AD dementias do not yet exist, but promising candidates have been identified over recent years. This review summarizes the current literature on cerebrospinal fluid biomarkers for the diagnosis of AD and other dementias.

Developing predictive CSF biomarkers-a challenge critical to success in Alzheimer's disease and neuropsychiatric translational medicine

The need to develop effective treatments for Alzheimer's disease has been confounded by repeated clinical failures where promising new chemical entities that have been extensively characterized in preclinical models of Alzheimer's disease have failed to show efficacy in the human disease state. This has been attributed to: the selection of drug targets that have yet to be shown as causal to the disease as distinct from being the result of the disease process, a lack of congruence in the animal models of Alzheimer's disease, wild-type and transgenic, to the human disease, and the enrollment of patients in proof of concept clinical trials who are at too advanced a stage of the disease to respond to any therapeutic. The development of validated biomarkers that can be used for disease diagnosis and progression is anticipated to improve patient enrollment in clinical trials, to develop new animal models and to identify new disease targets for drug discovery. The present review assesses the status of current efforts in developing CSF biomarkers for Alzheimer's disease and briefly discusses the status of CSF biomarker efforts in schizophrenia, depression, Parkinson's disease and multiple sclerosis.