Protein kinase A regulatory subunit distribution in medulloblastoma

<p>Abstract</p> <p>Background</p> <p>Previous studies showed a differential distribution of the four regulatory subunits of cAMP-dependent protein kinases inside the brain, that changed in rodent gliomas: therefore, the distribution of these proteins inside the brain can give information on the functional state of the cells. Our goal was to examine human brain tumors to provide evidence for a differential distribution of protein kinase A in different tumors.</p> <p>Methods</p> <p>The distribution of detergent insoluble regulatory (R1 and R2) and catalytic subunits of cAMP dependent kinases was examined in pediatric brain tumors by immunohistochemistry and fluorescent cAMP analogues binding.</p> <p>Results</p> <p>R2 is organized in large single dots in medulloblastomas, while it has a different appearance in other tumors. Fluorescent cAMP labelling was observed only in medulloblastoma.</p> <p>Conclusions</p> <p>A different distribution of cAMP dependent protein kinases has been observed in medulloblastoma.</p

Signal transduction events induced by extracellular guanosine 5′triphosphate in excitable cells

A better understanding of the physiological effects of guanosine-based purines should help clarify the complex subject of purinergic signalling. We studied the effect of extracellular guanosine 5′triphosphate (GTP) on the differentiation of two excitable cell lines that both have specific binding sites for GTP: PC12 rat pheochromocytoma cells and C2C12 mouse skeletal muscle cells. PC12 cells can be differentiated into fully functional sympathetic-like neurons with 50′00 ng ml−1 of nerve growth factor, whereas serum starvation causes C2C12 cells to differentiate into myotubes showing functional excitation–contraction coupling, with the expression of myosin heavy chain proteins. Our results show that GTP enhances the differentiation of both of these excitable cell lines. The early events in guanosine-based purine signal transduction appear to involve an increase in intracellular Ca2+ levels and membrane hyperpolarization. We further investigated the early activation of extracellular-regulated kinases and phosphoinositide 3-kinase in GTP-stimulated PC12 and C2C12 cells, respectively. We found that GTP promotes the activation of both kinases. Together, our results suggest that, even if there are some differences in the signalling pathways, GTP-induced differentiation in both cell lines is dependent on an increase in intracellular Ca2+

Comprehensive mRNA Expression Profiling Distinguishes Tauopathies and Identifies Shared Molecular Pathways

Background: Understanding the aetiologies of neurodegenerative diseases such as Alzheimer's disease (AD), Pick's disease (PiD), Progressive Supranuclear Palsy (PSP) and Frontotemporal dementia (FTD) is often hampered by the considerable clinical and molecular overlap between these diseases and normal ageing. The development of high throughput genomic technologies such as microarrays provide a new molecular tool to gain insight in the complexity and relationships between diseases, as they provide data on the simultaneous activity of multiple genes, gene networks and cellular pathways. Methodology/Principal Findings: We have constructed genome wide expression profiles from snap frozen post-mortem tissue from the medial temporal lobe of patients with four neurodegenerative disorders (5 AD, 5 PSP, 5 PiD and 5 FTD patients) and 5 control subjects. All patients were matched for age, gender, ApoE-e and MAPT (tau) haplotype. From all groups a total of 790 probes were shown to be differently expressed when compared to control individuals. The results from these experiments were then used to investigate the correlations between clinical, pathological and molecular findings. From the 790 identified probes we extracted a gene set of 166 probes whose expression could discriminate between these disorders and normal ageing. Conclusions/Significance: From genome wide expression profiles we extracted a gene set of 166 probes whose expression could discriminate between neurological disorders and normal ageing. This gene set can be further developed into an accurate microarray-based classification test. Furthermore, from this dataset we extracted a disease specific set of genes and identified two aging related transcription factors (FOXO1A and FOXO3A) as possible drug targets related to neurodegenerative disease

1H-NMR-Based Metabolic Profiling of Maternal and Umbilical Cord Blood Indicates Altered Materno-Foetal Nutrient Exchange in Preterm Infants

Background: Adequate foetal growth is primarily determined by nutrient availability, which is dependent on placental nutrient transport and foetal metabolism. We have used 1H nuclear magnetic resonance (NMR) spectroscopy to probe the metabolic adaptations associated with premature birth. Methodology: The metabolic profile in 1H NMR spectra of plasma taken immediately after birth from umbilical vein, umbilical artery and maternal blood were recorded for mothers delivering very-low-birth-weight (VLBW) or normo-ponderal full-term (FT) neonates. Principal Findings: Clear distinctions between maternal and cord plasma of all samples were observed by principal component analysis (PCA). Levels of amino acids, glucose, and albumin-lysyl in cord plasma exceeded those in maternal plasma, whereas lipoproteins (notably low-density lipoprotein (LDL) and very low-density lipoprotein (VLDL) and lipid levels were lower in cord plasma from both VLBW and FT neonates. The metabolic signature of mothers delivering VLBW infants included decreased levels of acetate and increased levels of lipids, pyruvate, glutamine, valine and threonine. Decreased levels of lipoproteins glucose, pyruvate and albumin-lysyl and increased levels of glutamine were characteristic of cord blood (both arterial and venous) from VLBW infants, along with a decrease in levels of several amino acids in arterial cord blood. Conclusion: These results show that, because of its characteristics and simple non-invasive mode of collection, cord plasma is particularly suited for metabolomic analysis even in VLBW infants and provides new insights into the materno-foetal nutrient exchange in preterm infants

Research protocol of the NeedYD-study (Needs in Young onset Dementia): a prospective cohort study on the needs and course of early onset dementia

Contains fulltext : 89407.pdf (publisher's version ) (Open Access)BACKGROUND: Early onset dementia has serious consequences for patients and their family members. Although there has been growing attention for this patient group, health care services are still mainly targeted at the elderly. Specific knowledge of the needs of early onset dementia patients and their families is limited but necessary for the development of adequate health care services and specific guidelines. This research project is mainly targeted at delineating the course of early onset dementia, the functional characteristics and needs of early onset dementia patients and their caregivers, the risk factors for institutionalization and the interaction with the caring environment. METHODS/DESIGN: The NeedYD-study (Needs in Young Onset Dementia) is a longitudinal observational study investigating early onset dementia patients and their caregivers (n = 217). Assessments are performed every six months over two years and consist of interviews and questionnaires with patients and caregivers. The main outcomes are (1) the needs of patients and caregivers, as measured by the Camberwell Assessment of Needs for the Elderly (CANE) and (2) neuropsychiatric symptoms, as measured by the NeuroPsychiatric Inventory (NPI). Qualitative analyses will be performed in order to obtain more in-depth information on the experiences of EOD patients and their family members. The results of this study will be compared with comparable data on late onset dementia from a historical cohort. DISCUSSION: The study protocol of the NeedYD-study is presented here. To our knowledge, this study is the first prospective cohort study in this research area. Although some limitations exist, these do not outweigh the strong points of this study design

Rodent Models of TDP-43 Proteinopathy: Investigating the Mechanisms of TDP-43-Mediated Neurodegeneration

Since the identification of phosphorylated and truncated transactive response DNA-binding protein 43 (TDP-43) as a primary component of ubiquitinated inclusions in amyotrophic lateral sclerosis and frontotemporal lobar degeneration with ubiquitin-positive inclusions, much effort has been directed towards ascertaining how TDP-43 contributes to the pathogenesis of disease. As with other protein misfolding disorders, TDP-43-mediated neuronal death is likely caused by both a toxic gain and loss of TDP-43 function. Indeed, the presence of cytoplasmic TDP-43 inclusions is associated with loss of nuclear TDP-43. Moreover, post-translational modifications of TDP-43, including phosphorylation, ubiquitination, and cleavage into C-terminal fragments, may bestow toxic properties upon TDP-43 and cause TDP-43 dysfunction. However, the exact neurotoxic TDP-43 species remain unclear, as do the mechanism(s) by which they cause neurotoxicity. Additionally, given our incomplete understanding of the roles of TDP-43, both in the nucleus and the cytoplasm, it is difficult to truly appreciate the detrimental consequences of aberrant TDP-43 function. The development of TDP-43 transgenic animal models is expected to narrow these gaps in our knowledge. The aim of this review is to highlight the key findings emerging from TDP-43 transgenic animal models and the insight they provide into the mechanisms driving TDP-43-mediated neurodegeneration

Evaluation of appendicitis risk prediction models in adults with suspected appendicitis

Background Appendicitis is the most common general surgical emergency worldwide, but its diagnosis remains challenging. The aim of this study was to determine whether existing risk prediction models can reliably identify patients presenting to hospital in the UK with acute right iliac fossa (RIF) pain who are at low risk of appendicitis. Methods A systematic search was completed to identify all existing appendicitis risk prediction models. Models were validated using UK data from an international prospective cohort study that captured consecutive patients aged 16–45 years presenting to hospital with acute RIF in March to June 2017. The main outcome was best achievable model specificity (proportion of patients who did not have appendicitis correctly classified as low risk) whilst maintaining a failure rate below 5 per cent (proportion of patients identified as low risk who actually had appendicitis). Results Some 5345 patients across 154 UK hospitals were identified, of which two‐thirds (3613 of 5345, 67·6 per cent) were women. Women were more than twice as likely to undergo surgery with removal of a histologically normal appendix (272 of 964, 28·2 per cent) than men (120 of 993, 12·1 per cent) (relative risk 2·33, 95 per cent c.i. 1·92 to 2·84; P < 0·001). Of 15 validated risk prediction models, the Adult Appendicitis Score performed best (cut‐off score 8 or less, specificity 63·1 per cent, failure rate 3·7 per cent). The Appendicitis Inflammatory Response Score performed best for men (cut‐off score 2 or less, specificity 24·7 per cent, failure rate 2·4 per cent). Conclusion Women in the UK had a disproportionate risk of admission without surgical intervention and had high rates of normal appendicectomy. Risk prediction models to support shared decision‐making by identifying adults in the UK at low risk of appendicitis were identified