Monthly Archives: September 2020

Relevant predictor of symptom persistence and response to treatment in melancholic depression interpreted as neurodegenerative in nature

Conversely, however, the parietal CSF volume reductions reported here are unlikely to be of neurodegenerative origin. Nevertheless, if we consider depression as a chronic and recurrent disease with multiple genetic and environmental determinants, complex models are plausible, and thus structural abnormalities of neurodegenerative origin may well coexist with alterations of another etiology across different brain areas over the course of the illness. In addition to the above ideas, the CSF alterations reported here seem to be of clinical relevance as, in our sample of melancholic patients, larger CSF volumes in the left Sylvian fissure were related to a smaller improvement of depressive symptomatology at discharge. This observation is in accordance with previous correlations obtained with closely related measures, such as regional CSF insular volume or gray matter content of the insular cortex, which were related to the time to remission of the depressive episode after treatment initiation. Indeed, we also observed a correlation between CSF volume increase and time to remission, although the result was no longer significant after Bonferroni correction for multiple comparisons. Furthermore, there is also functional evidence supporting the relationship between insular cortex and clinical outcome, such as the observations of a normalization of insular hyperactivity after clinical recovery or successful antidepressant treatment. Contrasting the results obtained with the two different image segmentation strategies used here, we observed that the CSF content of the left Sylvian fissure was only significantly increased when data were pre-processed using the ‘new segment’ algorithm. Although there is no ‘gold-standard’ for comparing the results obtained with the two pre-processing approaches, we validated the left Sylvian fissure CSF volume increase detected here under the ‘new segment’ approach with a non-automated ROI analysis. Left, but not right, Sylvian fissure showed a lower mean signal intensity in combination with a larger volume. Also, such a finding is in accordance with earlier studies reporting brain structural alterations in melancholia also using non-automated image analysis techniques. Furthermore, the same CSF increase was also detected using the ‘unified segmentation’ algorithm, Doxorubicin albeit at a non-significant level, suggesting a reduced sensitivity of the latter approach to detect regional changes in CSF volume. Parietal CSF volume decreases were also uniquely detected using the ‘new segment’ approach, although, in this case, we did not attempt to replicate the findings with a non-automated ROI approach since findings were located in less definite regions in anatomical terms. Global CSF measurements also differed between the two segmentation methods studied.

The complement cascade is a component of the innate immune system that plays a critical role in post-ischemic inflammation

Furthermore, by lowering the expression of the E1 and E2, additional cellular resources can be Bortezomib diverted towards production of the target protein. Even without any process optimization, our E3-dependent SUMO conjugation system yielded,5 mg/L of mono-sumoylated protein. Second, the system enables functional characterization of any of the sumoylation cascade enzymes while eliminating the concern for localization, downstream interactions, and the diversity of sumoylated proteins that can obscure similar analysis in eukaryotic hosts. Our system also produces physiologically relevant results. For instance, we observed that Smad4 was sumoylated primarily at K159, which is reported to be the major sumoylation site. We did not detect sumoylation at position K113, which was reported as a minor site of sumoylation in one report but was not sumoylated in another. We also did not detect SUMO-1 chains on target proteins in our E3-dependent system, which is in stark contrast to an earlier bacterial E3-independent sumoylation system. It should be noted, however, that the inability of MS analysis to reveal poly-sumoylation via K16 and K17 linkages on SUMO-1 could arise from low abundance and/or poor ionization efficiency of these species. Nonetheless, based on the high-intensity MS signal detected for the K159 SUMO-1 peptide, we conclude that no appreciable quantities of SUMO-1 chains are present. Overall, our system yields results that are entirely consistent with the known molecular biology of sumoylation. As a corollary, we show that engineered E3 variants can be expressed and functionally characterized in our system. This is significant because our bacterial SUMO-conjugation system provides a potentially less convoluted background for studying sumoylation. While in vitro reconstitution studies could also be used to eliminate these factors, our system obviates the need for purification of each cascade component and the corresponding need to modify each cascade component with a purification tag, which can affect enzyme function. Thus, we anticipate that our sumo-engineered E. coli system will be a useful new tool for illuminating the molecular details of the SUMO-conjugation process. Of the numerous peptides generated though sequential complement cleavage, the anaphylatoxins, C3a and C5a, are among the most potent of all known inflammatory mediators. By binding to their cognate receptors, the C3a receptor and C5a receptor, these peptides mediate their inflammatory effects across a variety of pathologic settings by promoting vascular permeability, leukocyte activation, and chemotaxis. Modulation of complement in animal models of stroke has proven effective in suppressing post-ischemic inflammation. Recently, a role for complement activation in tissue regeneration has been proposed. More specifically, complement may regulate the process of endogenous neurogenesis, as neural progenitor cells and immature neurons have been reported to express both C3aR and C5aR.

All these symptoms are regularly offer insight into the molecular evolution of this important oligomeric enzyme

Therefore, the aim of this study was to determine the quaternary structure of DHDPS from the agriculturally-important species, Vitis vinifera or the common grapevine. Here, we present a thorough characterization of the structure of Vv-DHDPS both in aqueous solution and the crystal state compared to BaDHDPS, an example of the typical bacterial tetramer. We show that Vv-DHDPS adopts a ‘back-to-back’ dimer-of-dimers consistent with the structure reported for N. sylvestris DHDPS, and subsequently demonstrate using molecular dynamics simulations that the ‘back-to-back’ architecture is important for stabilizing protein dynamics of the ‘tight’ dimer unit. This study suggests that DHDPS from plants adopt an alternative quaternary architecture to the typical bacterial form, thus offering insight into the molecular evolution of an important oligomeric enzyme. In our study of targeted sequencing of coding and conserved portions of the UMOD gene region, we did not identify any common non-synonymous coding variant that could account for the GWAS signal by itself. Rare variants were identified and verified, but they were not significantly enriched among individuals at the extremes of THP levels when the entire study population was considered. The V458L variant, which is predicted to have a AP24534 Src-bcr-Abl inhibitor damaging effect on protein function, showed significant association with eGFR in one but not both studies, association with THP, and no apparent effect in functional studies on protein aggregation or trafficking as observed for monogenic diseasecausing variants. Several previous studies have re-sequenced candidate genes identified through GWAS in order to identify novel rare genetic variants with potentially stronger associations with the phenotype than observed for the trait-associated variants in GWAS. More successful recent examples in the area of common, complex diseases include uric acid and gout and inflammatory bowel disease. Using 350 cases of Crohn’s disease and controls, investigators were able to identify multiple independent rare variants in 7 genes, some with large effect sizes. Similar to the present study, the variants identified did not account for the original GWAS signal. However, less success has been observed for many other common complex diseases, including fine-mapping of the 9p21 region in association with type 2 diabetes and coronary artery disease, and type 1 diabetes. There are currently many ongoing sequencing efforts that are focused on sequencing the exons of candidate genes, as well as whole-exome sequencing. The relative yield of this approach, as compared to whole genome sequencing and assessment of structural variation, remains unknown. Melancholic depression is a subtype of major depressive disorder that encompasses a constellation of distinctive clinical features such as anhedonia, distinct quality of mood and mood non-reactivity, psychomotor disturbances, feelings of guilt, early awakening, diurnal variation and anorexia. Specific neurobiological correlates such as cortisol dysregulation and altered sleep patterns have also been appreciated in melancholia.

To identify the molecular and morphologic signatures associated with chemotherapeutic response in OvCa

Ovarian carcinoma remains a leading cause of mortality from gynecologic cancer, with approximately 21,880 new cases and 13,850 deaths estimated in the United States in 2010. The standard treatment protocol for advanced-stage epithelial OvCa is cytoreductive surgery followed by platinum-based combination chemotherapy. However, the majority of patients eventually relapse with generally incurable disease, mainly due to the emergence of chemotherapy resistance. Early identification and differentiation of patients who are resistant to chemotherapy could lead to their enrollment in clinical trials with alternative therapeutics and is of utmost importance for improving the outcome of ovarian cancer. Understanding the molecular mechanisms for chemoresistance has been the subject of intense research. Various Regorafenib genomic methodologies have been applied to the study of OvCa to identify a gene signature associated with chemotherapy response. However, there is a lack of overlap between the discovered genes in different studies, possibly because of limited sample size in most studies. The Cancer Genome Atlas, a project of the National Cancer Institute and the National Human Genome Research Institute, generates a comprehensive catalog of genomic abnormalities with large-scale data sets that include cancers with the highest mortality rates including serous OvCa. In addition, the TCGA effort has led to the accumulation of a large set of tumor images in the repository. It is recognized that cell morphologies are intimately linked to multiple cell functions, such as cell growth, apoptosis, differentiation, and migration. Switches between different cell functions can be controlled by regulating cell shapes. It is reported that nuclear size is correlated with tumor prognosis in Stage III-IV ovarian cancer and is capable of distinguishing low- from high-grade serous OvCa. However, the molecular mechanism underlying this association remains unknown. The tumor image collections in TCGA provide the opportunity to systematically characterize the morphologic features associated with chemotherapy response and gene activity. In this study, we leverage the full scope of the TCGA database with a large population of patients, including gene expression and tumor images. Integration of the genomic and morphologic dimensions of OvCa will yield potential insights into mechanism of drug resistance and facilitate identification of novel system-level events for alternate therapeutic interventions. Several studies have described chemotherapy response in ovarian cancer using gene expression profiles, as summarized by Helleman et al. However, the number of ovarian cancer specimens used for the gene selection in those studies was relatively small, ranging from 6 to 119, and the corresponding gene sets discovered to be associated with platinum-based chemotherapy resistance exhibited a wide range of 14 to 1,727 genes where only seven genes were observed as an overlap and each between only two gene sets. Lack of overlap between the discovered gene sets is likely due to the limited sample size in most studies. However, ours is the first study performed on such a large scale, two genes in the 227-gene set, EPH receptor B3 and nuclear factor I/B, had been identified in one of the previous studies, and one gene, RNA binding protein 1, had been identified in a different study.

Components of the immune response and provides a background for interpretation of the results

Our goal was to identify topological bottlenecks genes that are involved in the innate immune response. We utilized inferred networks derived from transcriptional data from three different sources, and combined the results to identify candidate bottleneck genes that might play more important and/or universal roles in related TLR-mediated neuroprotection and innate immune processes. The first two sources are blood and brain genomic responses from a study of neuroprotection against stroke in mice using the TLR ligands, LPS, CpGODN, or brief middle cerebral artery occlusion to precondition. The brain dataset has been previously described and the blood dataset is described for the first time here. The third source is from a large TWS119 compendium study of innate immune response in mouse macrophages. The first two datasets examine innate immune responses induced by TLRs in the context of preconditioning-induced neuroprotection against stroke. The third dataset provides an isolated view of innate immune responses induced in macrophages by the administration of TLR ligands. Our hypothesis is that network analysis of transcriptional data from several systems responding to stimulation of TLR-mediated response will allow identification of key effectors of system function, in this case innate immune processes. Our computational analysis identified bottleneck genes for each dataset analyzed and determined major functional pathways that may be affected by these genes. When comparing all three datasets, we found only six conserved bottlenecks including Ifi47, Axud1, Ppp1r15a, Tgtp, Ifit1, and Oasl2. Ifit1 was further investigated by examining its conserved network neighborhood, which had several overlapping genes in each dataset. Finally, we validated the role of Ifit1 as a functional bottleneck in macrophages by showing that blocking expression of Ifit1 using siRNA dramatically reduced expression of the predicted first-order network genes Usp18 and M61. This data demonstrates that Ifit1 exerts a regulatory influence over important downstream immune genes when stimulated by LPS, though the mechanism of its action remains unclear. Using our novel approach, network construction using transcriptional data from multiple time course studies and identification of key components using topological analysis, we define six potential key modulators of innate immunity that may also contribute to the neuroprotective response produced by preconditioning. In a previous study the effects of siRNA knock-downs of 125 regulators had been assessed on a total of 126 target genes after an initial network-based analysis of TLR stimulation in dendritic cells was performed. The study focused only on transcriptional regulators and so does not include direct validation of any of our predicted shared bottlenecks. However, we assessed the regulatory coherence of the six members of the conserved Ifit1 neighborhood that were assayed in the study: Ifit1, Ifit3, Oasl1, Rsad2, Iigp2, and Irf7. We therefore assessed the correlation of expression profiles for each gene in response to the 125 regulator knock-downs inside the neighborhood versus other genes. This analysis revealed the in-group correlation to be 0.76 while the out-of-group correlation was 0.40. This is a slight improvement over the mean correlation of the neighbor genes that are not common between the networks. The profiles of each of the neighbors is shown as Supplemental Figure S3.