Proline dehydrogenase from Thermus thermophilus does not discriminate between FAD and FMN as cofactor

Flavoenzymes are versatile biocatalysts containing either FAD or FMN as cofactor. FAD often binds to a Rossmann fold, while FMN prefers a TIM-barrel or flavodoxin-like fold. Proline dehydrogenase is denoted as an exception: it possesses a TIM barrel-like fold while binding FAD. Using a riboflavin auxotrophic Escherichia coli strain and maltose-binding protein as solubility tag, we produced the apoprotein of Thermus thermophilus ProDH (MBP-TtProDH). Remarkably, reconstitution with FAD or FMN revealed that MBP-TtProDH has no preference for either of the two prosthetic groups. Kinetic parameters of both holo forms are similar, as are the dissociation constants for FAD and FMN release. Furthermore, we show that the holo form of MBP-TtProDH, as produced in E. coli TOP10 cells, contains about three times more FMN than FAD. In line with this flavin content, the crystal structure of TtProDH variant ¿ABC, which lacks helices aA, aB and aC, shows no electron density for an AMP moiety of the cofactor. To the best of our knowledge, this is the first example of a flavoenzyme that does not discriminate between FAD and FMN as cofactor. Therefore, classification of TtProDH as an FAD-binding enzyme should be reconsidered

Neural Signatures of Intransitive Preferences

It is often assumed that decisions are made by rank-ordering and thus comparing the available choice options based on their subjective values. Rank-ordering requires that the alternatives’ subjective values are mentally represented at least on an ordinal scale. Because one alternative cannot be at the same time better and worse than another alternative, choices should satisfy transitivity (if alternative A is preferred over B, and B is preferred over C, A should be preferred over C). Yet, individuals often demonstrate striking violations of transitivity (preferring C over A). We used functional magnetic resonance imaging to study the neural correlates of intransitive choices between gambles varying in magnitude and probability of financial gains. Behavioral intransitivities were common. They occurred because participants did not evaluate the gambles independently, but in comparison with the alternative gamble presented. Neural value signals in prefrontal and parietal cortex were not ordinal-scaled and transitive, but reflected fluctuations in the gambles’ local, pairing-dependent preference-ranks. Detailed behavioral analysis of gamble preferences showed that, depending on the difference in the offered gambles’ attributes, participants gave variable priority to magnitude or probability and thus shifted between preferring richer or safer gambles. The variable, context-dependent priority given to magnitude and probability was tracked by insula (magnitude) and posterior cingulate (probability). Their activation-balance may reflect the individual decision rules leading to intransitivities. Thus, the phenomenon of intransitivity is reflected in the organization of the neural systems involved in risky decision-making

A Role for Fibrillar Collagen Deposition and the Collagen Internalization Receptor Endo180 in Glioma Invasion

Glioblastoma multiforme (GBM, WHO grade IV) is the most common and most malignant of astrocytic brain tumors, and is associated with rapid invasion into neighboring tissue. In other tumor types it is well established that such invasion involves a complex interaction between tumor cells and locally produced extracellular matrix. In GBMs, surprisingly little is known about the associated matrix components, in particular the fibrillar proteins such as collagens that are known to play a key role in the invasion of other tumor types.In this study we have used both the Masson's trichrome staining and a high resolution multiple immunofluorescence labeling method to demonstrate that intratumoral fibrillar collagens are an integral part of the extracellular matrix in a subset of GBMs. Correlated with this collagen deposition we observed high level expression of the collagen-binding receptor Endo180 (CD280) in the tumor cells. Further, interrogation of multiple expression array datasets identified Endo180 as one of the most highly upregulated transcripts in grade IV GBMs compared to grade III gliomas. Using promoter analysis studies we show that this increased expression is, in part, mediated via TGF-β signaling. Functionally, we demonstrate that Endo180 serves as the major collagen internalization receptor in GBM cell lines and provide the first evidence that this activity is critical for the invasion of GBM cells through fibrillar collagen matrices.This study demonstrates, for the first time, that fibrillar collagens are extensively deposited in GBMs and that the collagen internalization receptor Endo180 is both highly expressed in these tumors and that it serves to mediate the invasion of tumor cells through collagen-containing matrices. Together these data provide important insights into the mechanism of GBM invasion and identify Endo180 as a potential target to limit matrix turnover by glioma cells and thereby restrict tumor progression

Low circulating concentrations of citrulline and FGF19 predict chronic cholestasis and poor survival in adult patients with chronic intestinal failure: development of a Model for End-Stage Intestinal Failure (MESIF risk score)

Contains fulltext : 205171.pdf (publisher's version ) (Open Access)BACKGROUND: Patients with chronic intestinal failure (CIF) often develop cholestatic liver injury, which may lead to liver failure and need for organ transplantation. OBJECTIVES: The aim of this study was to investigate whether citrulline (CIT) and the enterokine fibroblast growth factor 19 (FGF19) are associated with chronic cholestasis and survival in adult CIF patients, and to develop a risk score to predict their survival. METHODS: We studied 135 adult CIF patients on intravenous supplementation (>3 mo). Associations of plasma CIT and FGF19 with chronic cholestasis and survival were estimated by logistic and Cox regression models. A predictive risk score was developed and validated internally. RESULTS: Patients with chronic cholestasis (17%) had a reduced 5-y survival rate compared with patients without chronic cholestasis (38% and 62%, respectively). In multivariable analysis, low FGF19, low CIT, and female sex were associated with chronic cholestasis. Patients with low rather than high CIT or FGF19 also had reduced 5-y survival rates (29% compared with 69%; 54% compared with 66%, respectively). Risk factors identified in multivariable analysis of survival were low FGF19 (HR: 3.4), low CIT (HR: 3.3), and number of intravenous infusions per week (HR: 1.4). These 3 predictors were incorporated in a risk model of survival termed Model for End-Stage Intestinal Failure (MESIF) (C-statistic 0.78). The 5-y survival rates for patients with MESIF scores of 0 to 40 (n = 13) were 80%, 58%, and 14%, respectively. CONCLUSIONS: CIT and FGF19 predict chronic cholestasis and survival in this cohort of adult CIF patients, and the derived MESIF score is associated with their survival. Pending external validation, the MESIF score may help to identify patients for closer clinical monitoring or earlier referral to intestinal transplantation centers

Proteomic Serum Biomarkers and Their Potential Application in Cancer Screening Programs

Early diagnosis of cancer is of pivotal importance to reduce disease-related mortality. There is great need for non-invasive screening methods, yet current screening protocols have limited sensitivity and specificity. The use of serum biomarkers to discriminate cancer patients from healthy persons might be a tool to improve screening programs. Mass spectrometry based proteomics is widely applied as a technology for mapping and identifying peptides and proteins in body fluids. One commonly used approach in proteomics is peptide and protein profiling. Here, we present an overview of profiling methods that have the potential for implementation in a clinical setting and in national screening programs

The Arabidopsis thaliana SERK1 kinase domain spontaneously refolds to an active state in vitro

Auto-phosphorylating kinase activity of plant leucine-rich-repeat receptor-like kinases (LRR-RLK's) needs to be under tight negative control to avoid unscheduled activation. One way to achieve this would be to keep these kinase domains as intrinsically disordered protein (IDP) during synthesis and transport to its final location. Subsequent folding, which may depend on chaperone activity or presence of interaction partners, is then required for full activation of the kinase domain. Bacterially produced SERK1 kinase domain was previously shown to be an active Ser/Thr kinase. SERK1 is predicted to contain a disordered region in kinase domains X and XI. Here, we show that loss of structure of the SERK1 kinase domain during unfolding is intimately linked to loss of activity. Phosphorylation of the SERK1 kinase domain neither changes its structure nor its stability. Unfolded SERK1 kinase has no autophosphorylation activity and upon removal of denaturant about one half of the protein population spontaneously refolds to an active protein in vitro. Thus, neither chaperones nor interaction partners are required during folding of this protein to its catalytically active state

Effectiveness of Mindfulness-Based Cognitive Therapy in reducing psychological distress and improving sleep in patients with Inflammatory Bowel Disease:study protocol for a multicentre randomised controlled trial (MindIBD).

Background: Many patients with Inflammatory Bowel Diseases (IBD) suffer from psychological distress, fatigue and sleep disturbances, which are associated with reduced quality of life (QoL) and increased societal costs. Only limited psychosocial treatment options are available. As Mindfulness-Based Cognitive Therapy (MBCT) has demonstrated to improve psychological distress, QoL and sleep in other populations, MBCT might also be effective in patients with IBD. Methods: The MindIBD study is a prospective, multicentre, randomised controlled trial comparing MBCT plus Treatment As Usual (TAU) versus TAU alone in a targeted number of 136 IBD patients in remission, aged 16 years and older with at least mild psychological distress (Hospital Anxiety and Depression Scale (HADS) total score ≥ 11). Primary outcome is reduction of psychological distress post-intervention, measured by the HADS. In addition, the effect of MBCT on sleep quality (including actigraphy and electroencephalography recordings), fatigue, disease activity, perceived disease control, QoL and positive mental health will be examined. Assessments will be conducted at baseline and at 3, 6, 9 and 12 months follow-up. Cost-effectiveness will be determined and a process evaluation will be conducted. Discussion: This study will provide valuable insight into the clinical effect of MBCT on psychological distress, sleep quality, fatigue and QoL in IBD patients and into the cost-effectiveness. If effective, MBCT can be a valuable addition to the available psychosocial interventions for patients with IBD. Moreover, findings from this study may also be applicable in patients with other chronic conditions. Trial registration: ClinicalTrials.gov: NCT04646785, registered on 30/11/2020.</p

Effectiveness of Mindfulness-Based Cognitive Therapy in reducing psychological distress and improving sleep in patients with Inflammatory Bowel Disease:study protocol for a multicentre randomised controlled trial (MindIBD).

Background: Many patients with Inflammatory Bowel Diseases (IBD) suffer from psychological distress, fatigue and sleep disturbances, which are associated with reduced quality of life (QoL) and increased societal costs. Only limited psychosocial treatment options are available. As Mindfulness-Based Cognitive Therapy (MBCT) has demonstrated to improve psychological distress, QoL and sleep in other populations, MBCT might also be effective in patients with IBD. Methods: The MindIBD study is a prospective, multicentre, randomised controlled trial comparing MBCT plus Treatment As Usual (TAU) versus TAU alone in a targeted number of 136 IBD patients in remission, aged 16 years and older with at least mild psychological distress (Hospital Anxiety and Depression Scale (HADS) total score ≥ 11). Primary outcome is reduction of psychological distress post-intervention, measured by the HADS. In addition, the effect of MBCT on sleep quality (including actigraphy and electroencephalography recordings), fatigue, disease activity, perceived disease control, QoL and positive mental health will be examined. Assessments will be conducted at baseline and at 3, 6, 9 and 12 months follow-up. Cost-effectiveness will be determined and a process evaluation will be conducted. Discussion: This study will provide valuable insight into the clinical effect of MBCT on psychological distress, sleep quality, fatigue and QoL in IBD patients and into the cost-effectiveness. If effective, MBCT can be a valuable addition to the available psychosocial interventions for patients with IBD. Moreover, findings from this study may also be applicable in patients with other chronic conditions. Trial registration: ClinicalTrials.gov: NCT04646785, registered on 30/11/2020.</p

Effectiveness of Mindfulness-Based Cognitive Therapy in reducing psychological distress and improving sleep in patients with Inflammatory Bowel Disease:study protocol for a multicentre randomised controlled trial (MindIBD).

Background: Many patients with Inflammatory Bowel Diseases (IBD) suffer from psychological distress, fatigue and sleep disturbances, which are associated with reduced quality of life (QoL) and increased societal costs. Only limited psychosocial treatment options are available. As Mindfulness-Based Cognitive Therapy (MBCT) has demonstrated to improve psychological distress, QoL and sleep in other populations, MBCT might also be effective in patients with IBD. Methods: The MindIBD study is a prospective, multicentre, randomised controlled trial comparing MBCT plus Treatment As Usual (TAU) versus TAU alone in a targeted number of 136 IBD patients in remission, aged 16 years and older with at least mild psychological distress (Hospital Anxiety and Depression Scale (HADS) total score ≥ 11). Primary outcome is reduction of psychological distress post-intervention, measured by the HADS. In addition, the effect of MBCT on sleep quality (including actigraphy and electroencephalography recordings), fatigue, disease activity, perceived disease control, QoL and positive mental health will be examined. Assessments will be conducted at baseline and at 3, 6, 9 and 12 months follow-up. Cost-effectiveness will be determined and a process evaluation will be conducted. Discussion: This study will provide valuable insight into the clinical effect of MBCT on psychological distress, sleep quality, fatigue and QoL in IBD patients and into the cost-effectiveness. If effective, MBCT can be a valuable addition to the available psychosocial interventions for patients with IBD. Moreover, findings from this study may also be applicable in patients with other chronic conditions. Trial registration: ClinicalTrials.gov: NCT04646785, registered on 30/11/2020.</p