The interaction of schizophrenia-related proteins DISC1 and NDEL1, in light of the newly identified domain structure of DISC1

DISC1 and NDEL1 are both key proteins in cortical neurodevelopment, which are each also implicated in the pathogenesis of mental illness. That the two proteins interact with each other in a functionally important manner is well established, but two distinct binding domains for NDEL1 on DISC1 have been proposed. A partial domain structure for DISC1 has recently been described, consisting of 4 structured regions referred to as “D,” “I,” “S” and “C” respectively, with one of the NDEL1 binding sites lying in the “C” region of DISC1. In light of this domain structure, it can be deduced that this site is the likely location at which NDEL1 binds, although the other proposed site (which lies in the DISC1 “I” and “S” regions) may indirectly impact on DISC1-NDEL1 interactions through determination of the oligomeric state of DISC1

SYMPTOM SEVERITY IN SCHIZOPHRENIA PATIENTS WITH NPAS3, DYSBINDIN-1 AND/OR TRIOBP PROTEIN PATHOLOGY IN THEIR BLOOD SERUM: A PANSS-BASED FOLLOW UP STUDY

Background: It has been proposed that aggregation of specific proteins in the brain may be a pathological element in schizophrenia and other chronic disorders. Multiple such aggregating proteins have now been implicated through post mortem investigation, including NPAS3 (Neuronal PAS domain protein 3), dysbindin-1 (encoded by the DTNBP1, Dystrobrevin Binding Protein 1, gene) and TRIOBP (Trio-Binding Protein, multiple isoforms). While the presence of protein aggregates in the brain is interesting in terms of understanding pathology, it is impractical as a biomarker. These proteins were therefore investigated recently in blood serum of schizophrenia patients and controls, showing patients to have higher levels of NPAS3 in their serum generally. TRIOBP-1 and dysbindin-1 were also found in an insoluble state, implying aggregation, but did not clearly corresponding to disease state. Subject and methods: We revisit 47 of the originally recruited 50 patients with schizophrenia, all of whom are Croatian and aged between 18 and 72. We assessed their symptom specificity and severity using PANSS (the Positive and Negative Symptoms Scale), comparing those with NPAS3, insoluble dysbindin-1 and/or insoluble TRIOBP-1 in their blood serum to those lacking any such protein dysregulation. Results: The frequency of each individual potential protein pathology among these patients was too low for meaningful statistical analysis, however the 11 patients that displayed one or more of these pathologies (NPAS3, dysbindin-1, TRIOBP-1 and/or TRIOBP- 5/6) showed a subtle but significant increase in total PANSS scores compared to the 36 patients displaying none of the pathologies (p = 0.031), seemingly driven principally by increased scores on the general psychopathology scale. Conclusion: While the numbers of patients involved do not allow firm conclusions to be drawn at this time, this provides the first indication that disturbed proteostasis in blood serum, of proteins that aggregate in the brains of schizophrenia patients, may correlate with the severity of schizophrenia symptoms

MicroRNA-143 activation regulates smooth muscle and endothelial cell crosstalk in pulmonary arterial hypertension

Rationale: The pathogenesis of PAH remains unclear. The four microRNAs representing the miR-143 and miR-145 stem loops are genomically clustered. Objective: To elucidate the transcriptional regulation of the miR-143/145 cluster, and the role of miR-143 in PAH. Methods and Results: We identified the promoter region that regulates miR-143/145 miRNA expression in pulmonary artery smooth muscle cells (PASMCs). We mapped PAH-related signalling pathways, including estrogens receptor (ER), liver X factor/retinoic X receptor (LXR/RXR), TGF-β (Smads), and hypoxia (HRE) that regulated levels of all pri-miR stem loop transcription and resulting miRNA expression. We observed that miR-143-3p is selectively upregulated compared to miR-143-5p during PASMC migration. Modulation of miR-143 in PASMCs significantly altered cell migration and apoptosis. In addition, we found high abundance of miR-143-3p in PASMCs-derived exosomes. Using assays with pulmonary arterial endothelial cells (PAECs) we demonstrated a paracrine pro-migratory and pro-angiogenic effect of miR-143-3p enriched exosomes from PASMC. Quantitative PCR and in situ hybridisation showed elevated expression of miR-143 in calf models of PAH as well as in samples from PAH patients. Moreover, in contrast to our previous findings that had not supported a therapeutic role in vivo, we now demonstrate a protective role for miR-143 in experimental PH in vivo in miR-143-/- and antimiR143-3p-treated mice exposed to chronic hypoxia in both preventative and reversal settings. Conclusions: MiR-143-3p modulated both cellular and exosome-mediated responses in pulmonary vascular cells, while inhibition of miR-143-3p blocked experimental PH. Taken together these findings confirm an important role for the miR-143/145 cluster in PAH pathobiology

Turbulent velocity measurements in open channel bores

In an open channel, a sudden rise in free-surface elevation is associated with the development of a bore. The bore front is a hydrodynamic shock with a sharp discontinuity in terms of water depth and velocity field. In this study, some turbulent velocity measurements were conducted in breaking bores. The unsteady turbulent properties were analysed using three methods: an ensemble average (EA) technique based upon 20 repeated experiments, a variable interval time average (VITA) method based upon a single experiment, and the variable interval time average (VITA) method averaged over 20 experimental runs. The instantaneous free-surface and velocity measurements showed a marked effect of the bore front passage. The longitudinal velocity components were always characterised by a rapid flow deceleration at all vertical elevations, and some large fluctuations of all velocity components were recorded beneath the surge. The EA and VITA methods showed some comparable long-term trends superposed to some rapid turbulent fluctuations, as well as close results in terms of the turbulent Reynolds stress components. The VITA data based upon a single run presented some differences with the EA median results, but all methods exhibited comparable long-term trends superposed to rapid turbulent fluctuations. (C) 2011 Elsevier Masson SAS. All rights reserved

Disrupted in Schizophrenia 1 regulates the processing of reelin in the perinatal cortex

Disrupted in Schizophrenia 1 (DISC1) is a prominent gene in mental illness research, encoding a scaffold protein known to be of importance in the developing cerebral cortex. Reelin is a critical extracellular protein for development and lamination of the prenatal cortex and which has also been independently implicated in mental illness. Regulation of reelin activity occurs through processing by the metalloproteinases ADAMTS-4 and ADAMTS-5. Through cross-breeding of heterozygous transgenic DISC1 mice with heterozygous reeler mice, which have reduced reelin, pups heterozygous for both phenotypeswere generated. Fromthese,we determine that transgenic DISC1 leads to a reduction in the processing of reelin, with implications for its downstream signalling element Dab1. An effect of DISC1 on reelin processing was confirmed in vitro, and revealed that intracellular DISC1 affects ADAMTS-4 protein, which in turn is exported and affects processing of extracellular reelin. In transgenic rat cortical cultures, an effect of DISC1 on reelin processing could also be seen specifically in early, immature neurons, but was lost in calretinin and reelin-positive mature neurons, suggesting cell-type specificity. DISC1 therefore acts upstream of reelin in the perinatal cerebral cortex in a cell type/time specific manner, leading to regulation of its activity through altered proteolytic cleavage. Thus a functional link is demonstrated between two proteins, each of independent importance for both cortical development and associated cognitive functions leading to behavioural maladaptation and mental illness

Design and elaboration of a tractable tricyclic scaffold to synthesize druglike inhibitors of dipeptidyl peptidase-4 (DPP-4), antagonists of the C–C Chemokine Receptor Type 5 (CCR5), and highly potent and selective phosphoinositol-3 Kinase δ (PI3Kδ) inhibitors

A novel molecular scaffold has been synthesized, and its incorporation into new analogues of biologically active molecules across multiple target classes will be discussed. In these studies, we have shown use of the tricyclic scaffold to synthesize potent inhibitors of the serine peptidase DPP-4, antagonists of the CCR5 receptor, and highly potent and selective PI3K δ isoform inhibitors. We also describe the predicted physicochemical properties of the resulting inhibitors and conclude that the tractable molecular scaffold could have potential application in future drug discovery programs

The NDE1 genomic locus can affect treatment of psychiatric illness through gene expression changes related to microRNA-484

Genetic studies of familial schizophrenia in Finland have observed significant associations with a group of biologically related genes, DISCI1, NDE1,NDEL1, PDE4B and PDE4D, the 'DISCI network'. Here, we use gene expression and psychoactive medication use data to study their biological consequences and potential treatment implications. Gene expression levels were determined in 64 individuals from 18 families, while prescription medication information has been collected over a 10 -year period for 931 affected individuals. We demonstrate that the NDE1 SNP rs2242549 associates with significant changes in gene expression for 2908 probes (2542 genes), of which 794 probes (719 genes) were replicable. A significant number of the genes altered were predicted targets of microRNA-484 (p = 3.0 x 10(-8)), located on a non -coding exon of NDE1. Variants within the NM. locus also displayed significant genotype by gender interaction to early cessation of psychoactive medications metabolized by CYP2C19. Furthermore, we demonstrate that miR-484 can affect the expression of CYP2C19 in a cell culture system. Thus, variation at the IVDET locus may alter risk of mental illness, in part through modification of miR-484, and such modification alters treatment response to specific psychoactive medications, leading to the potential for use of this locus in targeting treatment.Peer reviewe

A comprehensive database of quality-rated fossil ages for Sahul\u27s Quaternary vertebrates

The study of palaeo-chronologies using fossil data provides evidence for past ecological and evolutionary processes, and is therefore useful for predicting patterns and impacts of future environmental change. However, the robustness of inferences made from fossil ages relies heavily on both the quantity and quality of available data. We compiled Quaternary non-human vertebrate fossil ages from Sahul published up to 2013. This, the FosSahul database, includes 9,302 fossil records from 363 deposits, for a total of 478 species within 215 genera, of which 27 are from extinct and extant megafaunal species (2,559 records). We also provide a rating of reliability of individual absolute age based on the dating protocols and association between the dated materials and the fossil remains. Our proposed rating system identified 2,422 records with high-quality ages (i.e., a reduction of 74%). There are many applications of the database, including disentangling the confounding influences of hypothetical extinction drivers, better spatial distribution estimates of species relative to palaeo-climates, and potentially identifying new areas for fossil discovery

PKA Phosphorylation of NDE1 Is DISC1/PDE4 Dependent and Modulates Its Interaction with LIS1 and NDEL1

Nuclear distribution factor E-homolog 1 (NDE1), Lissencephaly 1 (LIS1), and NDE-like 1 (NDEL1) together participate in essential neurodevelopmental processes, including neuronal precursor proliferation and differentiation, neuronal migration, and neurite out-growth. NDE1/LIS1/NDEL1 interacts with Disrupted in Schizophrenia 1 (DISC1) and the cAMP-hydrolyzing enzyme phosphodiesterase 4 (PDE4). DISC1, PDE4, NDE1, and NDEL1 have each been implicated as genetic risk factors for major mental illness. Here, we demonstrate that DISC1 and PDE4 modulate NDE1 phosphorylation by cAMP-dependent protein kinase A (PKA) and identify a novel PKA substrate site on NDE1 at threonine-131 (T131). Homology modeling predicts that phosphorylation at T131 modulates NDE1–LIS1 and NDE1–NDEL1 interactions, which we confirm experimentally. DISC1–PDE4 interaction thus modulates organization of the NDE1/NDEL1/LIS1 complex. T131-phosphorylated NDE1 is present at the postsynaptic density, in proximal axons, within the nucleus, and at the centrosome where it becomes substantially enriched during mitosis. Mutation of the NDE1 T131 site to mimic PKA phosphorylation inhibits neurite outgrowth. Thus PKA-dependent phosphorylation of the NDE1/LIS1/NDEL1 complex is DISC1–PDE4 modulated and likely to regulate its neural functions