The opioid effects of gluten exorphins:asymptomatic celiac disease

Gluten-containing cereals are a main food staple present in the daily human diet, including wheat, barley, and rye. Gluten intake is associated with the development of celiac disease (CD) and related disorders such as diabetes mellitus type I, depression, and schizophrenia. However, until now, there is no consent about the possible deleterious effects of gluten intake because of often failing symptoms even in persons with proven CD. Asymptomatic CD (ACD) is present in the majority of affected patients and is characterized by the absence of classical gluten-intolerance signs, such as diarrhea, bloating, and abdominal pain. Nevertheless, these individuals very often develop diseases that can be related with gluten intake. Gluten can be degraded into several morphine-like substances, named gluten exorphins. These compounds have proven opioid effects and could mask the deleterious effects of gluten protein on gastrointestinal lining and function. Here we describe a putative mechanism, explaining how gluten could "mask" its own toxicity by exorphins that are produced through gluten protein digestion

Characterization in humans of in vitro leukocyte maximal telomerase activity capacity (mTAC) and association with stress

Background: Telomerase, a cellular reverse transcriptase enzyme that can counteract telomere shortening and, in addition, preserves healthy cell function, constitutes a promising target for research into the pathological effects of stress on cellular aging. Previous studies that have included measures of telomerase have typically measured telomerase expression or activity under basal (resting) conditions. It is, however, challenging to reliably quantify or interpret these data because leukocyte telomerase is typically expressed at very low levels and is dynamic in nature. In contrast to basal measures, telomerase activity can be quantified in response to an ecologically-valid challenge such as mitogen stimulation in vitro. The potential advantage of this approach is that it may bypass the above-mentioned limitations to provide an indicator of individual differences in the capacity of the telomere biology system to respond to an immunological challenge. Objective: The aim of this study was to validate an in vitro measure of leukocyte maximal telomerase activity capacity (mTAC) for use in human studies of telomere biology, and to determine its association with measures of stress and stress responsivity. Methods: First, the optimal post-stimulation time course to characterize mTAC was established using an in vitro mitogen challenge (phytoheamagglutinin (PHA) supplemented with interleukin(IL)-2). Next, mTAC was measured in leukocytes and cortisol concentrations were assessed in saliva obtained from 28 healthy young women and men at different times of the day and before and after a standardized laboratory stressor. In addition, immune cell distributions prior to mitogen stimulation were determined by flow cytometry in a subset of the participants. Perceived (chronic) stress also was assessed using the Perceived Stress Scale. Results: The optimal time point to quantify human leukocyte mTAC was 72 hours after mitogen stimulation. mTAC exhibited substantial within-subject stability across time and was not influenced by situational factors including time of day, cortisol concentration, acute stress exposure, and immune cell distribution. A significant proportion of the between-subject variability in mTAC was associated with measures of stress and stress responsivity. Particuarly, there was a 25% difference in mTAC between subjects reporting high compared to medium or low levels of perceived (chronic) stress. Also, individual differences in the cortisol response to stress-exposure accounted for as much as 32% of the variation in mTAC. Conclusion: Based collectively on these findings, it appears that mTAC may represent a potentially useful individual difference measure in stress-related studies of the human telomere biology system.Hintergrund: Telomerase, ein zelluläres Transkriptionsenzym, das der Telomerverkürzung entgegenwirkt und wichtig ist für gesunde Zellfunktion, ist ein vielversprechender Biomarker hinsichtlich pathologischer Folgen von Stress auf zelluläre Alterungsprozesse. Bisherige Studien zur Messung von Telomeraseaktivität oder -expression haben dies meistens unter basalen Bedingungen durchgeführt. Basale Telomerase-Werte sind jedoch aufgrund der niedrigen Expressionsrate und der dynamischen Regulation der Telomerase in Leukozyten sehr schwierig zu messen und zu interpretieren. Im Gegensatz zur basalen Expressionsrate kann Telomerase-Aktivität im Rahmen eines ökologisch-validen Challenge Tests wie der in vitro Mitogen-Stimulation quantifiziert werden. Ein potentieller Vorteil dieses Verfahrens ist, dass dadurch die o.a. Einschränkungen der Interpretierbarkeit der basalen Telomerase-Aktivität umgangen werden können, und man somit die Möglichkeit hat, individuelle Unterschiede zu erfassen in der Kapazität des Telomersystems auf einem immunologischen Stimulus zu reagieren. Ziel: Das Ziel der Studie bestand in der Entwicklung und Validierung eines Maßes der maximalen Telomerase-Aktivitätskapazität (mTAC) zur Nutzung in Humanstudien im Bereich der Telomer-Biologie. Außerdem wurde der Zusammenhang dieses Maßes mit Stress bzw. Stressreaktivität untersucht. Methoden: Zuerst wurde der optimale post-stimulative Zeitverlauf zur mTAC-Charakterisierung mit einem in vitro Mitogen-Challenge-Protokoll (PHA ergänzt durch Interleukin(IL)-2) bestimmt. Danach wurden sowohl mTAC in Leukozyten und Cortisolkonzentrationen im Speichel von 28 jungen gesunden Proband/innen zu verschiedenen Messzeitpunkten im Verlauf des Tages und im Rahmen eines standardisierten Paradigmas zur Induktion psychosozialen Stresses im Labor gemessen. Darüber hinaus wurde in einem Teil der Stichprobe Durchflusszytometrie verwendet, um die Immunzell-Verteilung vor Stimulation zu bestimmen. Die wahrgenommene (chronische) Stressbelastung wurde durch die Perceived Stress Scale erfasst. Resultate: Der optimale Zeitpunkt zur Quantifizierung von mTAC in humanen Leukozyten liegt bei 72 Stunden nach Mitogen-Stimulation. mTAC weist eine erhebliche Stabilität innerhalb von Personen auf und wird nicht durch situationsbedingte Faktoren wie Tageszeit, Cortisol, akute Stressexposition und Immunzell-Verteilung beeinflusst. Ein signifikanter Anteil der Varianz zwischen Personen in mTAC wird durch chronische Stressbelastung und biologische Stressreaktivität erklärt. Insbesondere waren mTAC-Werte bei Personen mit hoher wahrgenommener Stressbelastung um 25% niedriger im Vergleich zu Probanden mit mittlerem oder niedriger wahrgenommener Stressbelastung. Außerdem erklärten individuelle Unterschiede in der Cortisolreaktion auf Laborstressexposition 32% der Varianz von mTAC. Fazit: Basierend auf diesen Ergebnissen kann man schlussfolgern, dass mTAC einen nützlichen individuellen Marker für stressbezogene Humanstudien im Bereich der Telomerbiologie darstellt

The opioid effects of gluten exorphins: asymptomatic celiac disease

Gluten-containing cereals are a main food staple present in the daily human diet, including wheat, barley, and rye. Gluten intake is associated with the development of celiac disease (CD) and related disorders such as diabetes mellitus type I, depression, and schizophrenia. However, until now, there is no consent about the possible deleterious effects of gluten intake because of often failing symptoms even in persons with proven CD. Asymptomatic CD (ACD) is present in the majority of affected patients and is characterized by the absence of classical gluten-intolerance signs, such as diarrhea, bloating, and abdominal pain. Nevertheless, these individuals very often develop diseases that can be related with gluten intake. Gluten can be degraded into several morphine-like substances, named gluten exorphins. These compounds have proven opioid effects and could mask the deleterious effects of gluten protein on gastrointestinal lining and function. Here we describe a putative mechanism, explaining how gluten could \u201cmask\u201d its own toxicity by exorphins that are produced through gluten protein digestion

Inflammatory measures in depressed patients with and without a history of adverse childhood experiences

Background: Major depressive disorder (MDD) is a complex psychiatric condition with different subtypes and etiologies. Exposure to adverse childhood experiences (ACE) is an important risk factor for the development of MDD later in life. Evidence suggests that pro-inflammatory processes may convey this risk as both MDD and ACE have been related to increased levels of inflammation. In the present study, we aimed to disentangle the effects of MDD and ACE on inflammation levels. Methods: Markers of inflammation (plasma interleukin(IL)-6 and high sensitive C-reactive protein (hsCRP) concentrations, white blood cell (WBC) count and a composite inflammation score (CIS) combining all three) were assessed in 23 MDD patients with ACE, 23 MDD patients without ACE, 21 healthy participants with ACE, and 21 healthy participants without ACE (mean age: 35 +/- 11 (SD) years). None of the patients and participants was taking psychotropic medication. ACE was assessed with the Early Trauma Inventory (ETI) and was defined as moderate to severe exposure to sexual or physical abuse. Results: Group differences in the different inflammatory measures were observed. MDD patients with ACE showed significantly higher IL-6 concentrations (p = 0.018), higher WBC counts (p = 0.003) and increased general inflammation levels as indicated by the CIS (p = 0.003) compared to healthy controls. In contrast, MDD patients without ACE displayed similar inflammation levels to the control group (p = 0.93). Conclusion: We observed elevated inflammation in MDD patients with a history of ACE, which could indicate a subtype of "inflammatory depression". Accordingly, MDD patients with ACE might potentially benefit from anti-inflammatory therapies

A structurally informed autotransporter platform for efficient heterologous protein secretion and display.

<p>Abstract</p> <p>Background</p> <p>The self-sufficient autotransporter (AT) pathway, ubiquitous in Gram-negative bacteria, combines a relatively simple protein secretion mechanism with a high transport capacity. ATs consist of a secreted passenger domain and a β-domain that facilitates transfer of the passenger across the cell-envelope. They have a great potential for the extracellular expression of recombinant proteins but their exploitation has suffered from the limited structural knowledge of carrier ATs. Capitalizing on its crystal structure, we have engineered the <it>Escherichia coli</it> AT Hemoglobin protease (Hbp) into a platform for the secretion and surface display of heterologous proteins, using the <it>Mycobacterium tuberculosis</it> vaccine target ESAT6 as a model protein.</p> <p>Results</p> <p>Based on the Hbp crystal structure, five passenger side domains were selected and one by one replaced by ESAT6, whereas a β-helical core structure (β-stem) was left intact. The resulting Hbp-ESAT6 chimeras were efficiently and stably secreted into the culture medium of <it>E. coli</it>. On the other hand, Hbp-ESAT6 fusions containing a truncated β-stem appeared unstable after translocation, demonstrating the importance of an intact β-stem. By interrupting the cleavage site between passenger and β-domain, Hbp-ESAT6 display variants were constructed that remain cell associated and facilitate efficient surface exposure of ESAT6 as judged by proteinase K accessibility and whole cell immuno-EM analysis. Upon replacement of the passenger side domain of an alternative AT, EspC, ESAT6 was also efficiently secreted, showing the approach is more generally applicable to ATs. Furthermore, Hbp-ESAT6 was efficiently displayed in an attenuated <it>Salmonella typhimurium</it> strain upon chromosomal integration of a single encoding gene copy, demonstrating the potential of the Hbp platform for live vaccine development.</p> <p>Conclusions</p> <p>We developed the first structurally informed AT platform for efficient secretion and surface display of heterologous proteins. The platform has potential with regard to the development of recombinant live vaccines and may be useful for other biotechnological applications that require high-level secretion or display of recombinant proteins by bacteria.</p

Inflammatory Measures in Depressed Patients With and Without a History of Adverse Childhood Experiences

Background: Major depressive disorder (MDD) is a complex psychiatric condition with different subtypes and etiologies. Exposure to adverse childhood experiences (ACE) is an important risk factor for the development of MDD later in life. Evidence suggests that pro-inflammatory processes may convey this risk as both MDD and ACE have been related to increased levels of inflammation. In the present study, we aimed to disentangle the effects of MDD and ACE on inflammation levels.Methods: Markers of inflammation (plasma interleukin(IL)-6 and high sensitive C-reactive protein (hsCRP) concentrations, white blood cell (WBC) count and a composite inflammation score (CIS) combining all three) were assessed in 23 MDD patients with ACE, 23 MDD patients without ACE, 21 healthy participants with ACE, and 21 healthy participants without ACE (mean age: 35 ± 11 (SD) years). None of the patients and participants was taking psychotropic medication. ACE was assessed with the Early Trauma Inventory (ETI) and was defined as moderate to severe exposure to sexual or physical abuse.Results: Group differences in the different inflammatory measures were observed. MDD patients with ACE showed significantly higher IL-6 concentrations (p = 0.018), higher WBC counts (p = 0.003) and increased general inflammation levels as indicated by the CIS (p = 0.003) compared to healthy controls. In contrast, MDD patients without ACE displayed similar inflammation levels to the control group (p = 0.93).Conclusion: We observed elevated inflammation in MDD patients with a history of ACE, which could indicate a subtype of “inflammatory depression”. Accordingly, MDD patients with ACE might potentially benefit from anti-inflammatory therapies

Direct Visualization by Cryo-EM of the Mycobacterial Capsular Layer: A Labile Structure Containing ESX-1-Secreted Proteins

The cell envelope of mycobacteria, a group of Gram positive bacteria, is composed of a plasma membrane and a Gram-negative-like outer membrane containing mycolic acids. In addition, the surface of the mycobacteria is coated with an ill-characterized layer of extractable, non-covalently linked glycans, lipids and proteins, collectively known as the capsule, whose occurrence is a matter of debate. By using plunge freezing cryo-electron microscopy technique, we were able to show that pathogenic mycobacteria produce a thick capsule, only present when the cells were grown under unperturbed conditions and easily removed by mild detergents. This detergent-labile capsule layer contains arabinomannan, α-glucan and oligomannosyl-capped glycolipids. Further immunogenic and proteomic analyses revealed that Mycobacterium marinum capsule contains high amounts of proteins that are secreted via the ESX-1 pathway. Finally, cell infection experiments demonstrated the importance of the capsule for binding to cells and dampening of pro-inflammatory cytokine response. Together, these results show a direct visualization of the mycobacterial capsular layer as a labile structure that contains ESX-1-secreted proteins