Automated identification of native peptides from human body fluids by means of mass spectrometry

Im Rahmen der Arbeit wurde eine Methodik zur umfassenden und automatischen Identifizierung von nativen Peptiden aus Extrakten komplexer biologischer Quellen entwickelt und am Beispiel des humanen Hämofiltrats angewendet. Die Firma BioVisioN führt seit der Gründung Forschung auf dem Gebiet der Peptide und kleinen Proteine mit dem Ziel, diagnostisch und therapeutisch relevante Substanzen zu finden, durch. Die Analyse sogenannter Peptidome, der qualitativen und quantitativen Beschreibung aller nativen Peptide und kleinen Proteinen bis ca. 15 kDa, ist als Analogon zur Proteom-Analytik zu verstehen, welche sich umfassend mit Proteinen beschäftigt. Quantitativ wird ein Peptidom über die Kombination chromatographischer Trennung und Fraktionierung mit der massenspektrometrischen „Inventarisierung“ der einzelnen Peptidspezies sowie den relativen Konzentrationen in der Probe erfasst, welches an anderer Stelle ausführlich beschrieben ist. Das Ergebnis einer solchen Peptidomanalyse besteht aus einer Peptidkarte, die die Peptide der Probe repräsentativ abbildet. Die Qualität eines Peptidoms wird über die Massen der Peptide, deren Aminosäuresequenzen und Elutionsverhalten und weitere biologische Informationen beschrieben. Zu diesen Zweck wird der Begriff des Peptide-Inventory eingeführt. Ein Inventory besteht aus allen verfügbaren Informationen nativer Peptide einer Quelle. Zu Beginn der Arbeit standen mit der reproduzierbaren Erstellung von Peptidbanken und deren systematischer Kartierung über MALDI-MS bereits zwei Werkzeuge zur Verfügung, um Daten eines Inventories zu erheben. Lediglich für die Erzeugung der Sequenzdaten wurde mit dem Edman-Abbau zwar eine etablierte, aber viel zu langsame und wenig sensitive Methode eingesetzt. Hier wurde der Ersatz durch eine schnelle und leicht zu automatisierenden Methode angestrebt. Die massenspektrometrische Sequenzierung über MS/MS mit anschließender Datenbanksuche ist ein aus der Proteom-Analytik durchaus bekanntes Verfahren, musste aber für die Analyse der nativen Peptide in einigen Bereichen modifiziert werden. Obwohl die Massenspektrometrie Peptide direkt aus komplexen Mischungen heraus identifizieren kann, stellte sich schnell heraus, dass die vorliegende biologische Beispielprobe (humanes Blutfiltrat) zu komplex war, um sie direkt für die geplante Sequenzierung einzusetzen. Es wurde eine erneute Auftrennung und Feinkartierung der Peptidbank notwendig. Jede dritte Fraktion wurde rechromatographiert und anschließend wiederum kartiert. Die entstandenen 97 Peptidkarten enthalten im Linear Modus ca. 100.000 Signale und im Reflektron Modus ca. 30.000 Signale, so dass nach der Feinkartierung > 10.000 native, im menschlichen Körper zirkulierende Peptide durch diese Methode dargestellt werden können. Zur Automatisierung der Kartierungsmessungen mit MALDI-MS wurde im Laufe dieser Arbeit ein Autosampler für ein MALDI-TOF-MS-System entwickelt und implementiert (DiskJockey). Das System hat eine Kapazität von 20 MALDI-Targets und ist vollständig über die Gerätesoftware steuerbar, so dass MALDI-MS-Messungen vollständig automatisiert über mehrere Tage ablaufen können. Zur Erzeugung der Sequenzdaten wurde eine Kombination aus elektrischer Ionenfalle und Datenbanksuche angewendet. Um zu gewährleisten, dass nur die zuvor kartierten Peptide einer MS/MS-Messung unterzogen werden, wurde das Softwaretool Alcatrap entwickelt. Diese Software übernimmt aus MALDI-MS-Messungen die Werte der monoisotopischen Peaks, überführt sie in mehrfach geladene Spezies und erstellt sowohl eine Methode für das MS-Gerät, als auch eine in die Gerätesoftware importierbare Arbeitsliste. Hierbei wird jeweils die Kollisionsenergie in Abhängigkeit der m/z-Wertes dynamisch gesetzt. Um den Datentransfer vom Fragmentspektrum zur Datenbanksuchmaschine zu gewährleisten, wurde mit „D2M“ eine weitere Softwareschnittstelle entwickelt. Die Erstellung des Inventories aus humanem Hämofiltrat liefert 1.225 verschiedene native, im menschlichen Blut zirkulierende Peptide aus 146 Proteinvorläufern. Darunter befinden sich mehrere Peptide, die neben ihrer physiologischen Bedeutung auch eine potenzielle medizinische Relevanz besitzen. Weiterhin ist auch der dynamische Bereich von acht Größenordnungen, in dem Sequenzen erzeugt wurden, vergleichbar mit dem des menschlichen Blutes. Eine Charakterisierung von Peptidomen ist in diesem Umfang bisher noch nicht durchgeführt worden und stellt eine Neuerung in der Proteomforschung dar. Die Studie ist durchaus vergleichbar mit kürzlich veröffentlichten umfangreichen Proteomstudien aus menschlichem Plasma und Serum und stellt eine Ergänzung dieser für den Bereich der Peptide und kleinen Proteine dar. Limitierungen bei der Identifizierung von Peptiden mit der Ionenfalle wurden analysiert und mit der Adaptierung des Peptide-Inventory Konzepts auf hochauflösende Quadrupol-Time-of-Flight Massenspektrometer zufriedenstellend gelöst. In diesem Rahmen wurde eine Methode entwickelt, die es ermöglicht, native Peptide bis zu einem Molekulargewicht von bis zu 8.500 Da direkt aus der komplexen Mischung zu fragmentieren und über eine Datenbanksuche zu identifizieren. Außerdem konnte exemplarisch gezeigt werden, dass durch die größere Massengenauigkeit und das größere Auflösungsvermögen des QTOF die Datenbanksuche wesentlich effektiver ist und durch die Kombination von Rechromatographie und QTOF-MS/MS nahezu jedes Signal einer Peptidbank der Identifizierung zugänlich gemacht werden kann. Sowohl die integrierte Methodik der Herstellung eines Peptide-Inventories, als auch die in dieser Arbeit erzielten Ergebnisse von nativen Peptiden in humanem Blut stellen wissenschaftliche Neuerungen dar, auf denen eine weitergehende Peptidom-Analytik aufsetzen kann

Практический опыт развития комплексной системы экологического просвещения в образовательной организации

В статье представлены разработанные и апробированные в образовательной организации новые подходы, механизмы и инструменты по одному из приоритетных направлений развития страны в части формирования экологического культуры вузовской молодежи с целью повышения познавательной активности, уровня экологических знаний в области гармоничного развития человека и природы, устойчивого интереса к экологическим проблемам современности, воспитания и привития бережного отношения к окружающей природе.The article presents new approaches, mechanisms and tools developed and tested in the educational organization in one of the priority directions of the country's development in terms of forming the ecological culture of university youth in order to increase cognitive activity, the level of ecological knowledge in the field of harmonious development of man and nature, and a steady interest in environmental problems of modernity, upbringing and inculcation of respect for nature

Peptide Fingerprinting of Alzheimer's Disease in Cerebrospinal Fluid: Identification and Prospective Evaluation of New Synaptic Biomarkers

<p><b>Background:</b> Today, dementias are diagnosed late in the course of disease. Future treatments have to start earlier in the disease process to avoid disability requiring new diagnostic tools. The objective of this study is to develop a new method for the differential diagnosis and identification of new biomarkers of Alzheimer's disease (AD) using capillary-electrophoresis coupled to mass-spectrometry (CE-MS) and to assess the potential of early diagnosis of AD.</p> <p><b>Methods and Findings:</b> Cerebrospinal fluid (CSF) of 159 out-patients of a memory-clinic at a University Hospital suffering from neurodegenerative disorders and 17 cognitively-healthy controls was used to create differential peptide pattern for dementias and prospective blinded-comparison of sensitivity and specificity for AD diagnosis against the Criterion standard in a naturalistic prospective sample of patients. Sensitivity and specificity of the new method compared to standard diagnostic procedures and identification of new putative biomarkers for AD was the main outcome measure. CE-MS was used to reliably detect 1104 low-molecular-weight peptides in CSF. Training-sets of patients with clinically secured sporadic Alzheimer's disease, frontotemporal dementia, and cognitively healthy controls allowed establishing discriminative biomarker pattern for diagnosis of AD. This pattern was already detectable in patients with mild cognitive impairment (MCI). The AD-pattern was tested in a prospective sample of patients (n = 100) and AD was diagnosed with a sensitivity of 87% and a specificity of 83%. Using CSF measurements of beta-amyloid1-42, total-tau, and phospho(181)-tau, AD-diagnosis had a sensitivity of 88% and a specificity of 67% in the same sample. Sequence analysis of the discriminating biomarkers identified fragments of synaptic proteins like proSAAS, apolipoprotein J, neurosecretory protein VGF, phospholemman, and chromogranin A.</p> <p><b>Conclusions:</b> The method may allow early differential diagnosis of various dementias using specific peptide fingerprints and identification of incipient AD in patients suffering from MCI. Identified biomarkers facilitate face validity for the use in AD diagnosis.</p&gt

Usefulness of the Athlete Burnout Questionnaire (ABQ) as a screening tool for the detection of clinically relevant burnout symptoms among young elite athletes

Objectives: Having psychometrically sound instruments is essential to the understanding of the determinants and consequences of athlete burnout. Therefore, this study examines the psychometric properties of a German version of the Athlete Burnout Questionnaire (ABQ) and its usefulness as a screening tool for the detection of clinically relevant burnout symptoms. Design: Prospective study. Method: 257 young elite athletes were recruited from Swiss Olympic Sport Classes (37% females; M = 16.8 years, SD = 1.4). 197 students were assessed a second time after six months. All students filled in a standardized questionnaire about domain-specific and domain-unspecific burnout symptoms, depressive symptoms, stress, and life satisfaction. Results: Confirmatory factor analysis supported the three-factor structure of the ABQ. Moreover, all subscales had acceptable internal consistency. Support was also found for the convergent validity of the ABQ; all subscales were positively correlated with perceived stress, burnout and depression, whereas negative correlations existed with life satisfaction. By contrast, some ABQ subscales shared only limited variance, the three ABQ subscales did not predict each other across time, and none of the ABQ subscales was suitable for the screening of clinically relevant burnout symptoms. Conclusions: While the factor structure and internal consistency of the ABQ was supported, our study corroborates previous concerns about the psychometric properties and validity of the ABQ. While the ABQ has advanced research on athlete burnout, we hold that further debates about the most suitable way to assess burnout among elite athletes are urgently needed

A database of naturally occurring human urinary peptides and proteins for use in clinical applications

Owing to its availability, ease of collection and correlation with (patho-) physiology, urine is an attractive source for clinical proteomics. However, the lack of comparable datasets from large cohorts has greatly hindered development in this field. Here we report the establishment of a high resolution proteome database of naturally occurring human urinary peptides and proteins - ranging from 800-17,000 Da - from over 3,600 individual samples using capillary electrophoresis coupled to mass spectrometry, yielding an average of 1,500 peptides per sample. All processed data were deposited in an SQL database, currently containing 5,010 relevant unique urinary peptides that serve as classifiers for diagnosis and monitoring of diseases, including kidney and vascular diseases. Of these, 352 have been sequenced to date. To demonstrate the applicability of this database, two examples of disease diagnosis were provided: For renal damage diagnosis, patients with a specific renal disease were identified with high specificity and sensitivity in a blinded cohort of 131 individuals. We further show definition of biomarkers specific for immunosuppression and complications after transplantation (Kaposi's sarcoma). Due to its high information content, this database will be a powerful tool for the validation of biomarkers for both renal and non-renal diseases

Do exercise and fitness buffer against stress among Swiss police and emergency response service officers?

Objectives: During the past three decades, researchers from many disciplines have been interested in whether exercise can help people to cope better with stress. Past research examining the stress buffering effects of exercise, however, is limited by small sample sizes, poorly validated measures of stress, exercise and health, and the exclusion of samples that are at-risk for chronic stress exposure. The purpose of the present study, therefore, was to address these limitations by exploring the stress buffering effects of exercise and fitness in a sample of police and emergency response service officers

Differences in mental health outcomes between adolescent elite athletes and peers not engaged in elite sport

Elite athletes are confronted with various challenges, pressures and stressors. Due to their status as student and athlete, adolescent elite athletes are exposed to a double burden of stress (pressure to be simultaneously successful in school and elite sport), which adds to the general risk for psychological problems in this developmental period. To facilitate the combination of elite sport and education, almost all cantons in Switzerland have established schools, which offer a special track for adolescent elite athletes. We examine (i) whether adolescent elite athletes differ from controls in a series of mental health outcomes, (ii) whether links between perceived stress and mental health symptoms are particularly strong among adolescent elite athletes, and (iii) whether perceived stress and training/competitive load interact to explain variance in mental health. Cross-sectional data from 156 athletes (134 from sport classes, 22 from regular classes) and 150 non-athletic controls (peers not engaged in elite sport) were analysed. All students were recruited from Swiss Olympic Partner schools, and attended grade 10-14. In total, 5–19% of the students reported moderate-to-severe mental health symptoms. With regard to depressive, burnout and insomnia symptoms, no significant differences were found between athletes and controls. A consistent link was observed between higher stress perceptions and more frequent mental health symptoms. However, engaging in elite sport did not seem to be an additional source of distress (or vulnerability factor) among adolescents with moderate-to-high stress levels. High training/competitive load did not amplify the association between perceived stress and mental health symptoms in elite athletes. Currently, no comprehensive framework or model of care exists to support and respond to mental health needs of young elite athletes. Our findings show that it is time to address these challenges to prevent mental health issues and ensure that young athletes can flourish while developing their full potential

Rapid and Deep Proteomes by Faster Sequencing on a Benchtop Quadrupole Ultra-High-Field Orbitrap Mass Spectrometer

Shotgun proteomics is a powerful technology for global analysis of proteins and their post-translational modifications. Here, we investigate the faster sequencing speed of the latest Q Exactive HF mass spectrometer, which features an ultra-high-field Orbitrap mass analyzer. Proteome coverage is evaluated by four different acquisition methods and benchmarked across three generations of Q Exactive instruments (ProteomeXchange data set PXD001305). We find the ultra-high-field Orbitrap mass analyzer to be capable of attaining a sequencing speed above 20 Hz, and it routinely exceeds 10 peptide spectrum matches per second or up to 600 new peptides sequenced per gradient minute. We identify 4400 proteins from 1 μg of HeLa digest using a 1 h gradient, which is an approximately 30% improvement compared to that with previous instrumentation. In addition, we show that very deep proteome coverage can be achieved in less than 24 h of analysis time by offline high-pH reversed-phase peptide fractionation, from which we identify more than 140 000 unique peptide sequences. This is comparable to state-of-the-art multiday, multienzyme efforts. Finally, the acquisition methods are evaluated for single-shot phosphoproteomics, where we identify 7600 unique HeLa phosphopeptides in one gradient hour and find the quality of fragmentation spectra to be more important than quantity for accurate site assignment

Perceived fitness protects against stress-based mental health impairments among police officers who report good sleep

Objectives: This study examined a cognitive stress-moderation model that posits that the harmful effects of chronic stress are decreased in police officers who perceive high levels of physical fitness. It also determined whether the stress-buffering effect of perceived fitness is influenced by officers' self-reported sleep. Methods: A total of 460 police officers (n=116 females, n=344 males, mean age: M=40.7; SD=9.7) rated their physical fitness and completed a battery of self-report stress, mental health, and sleep questionnaires. Three-way analyses of covariance were performed to examine whether officers' self-reported mental health status depends on the interaction between stress, perceived fitness and sleep. Results: Highly stressed officers perceived lower mental health and fitness and were overrepresented in the group of poor sleepers. Officers with high fitness self-reports revealed increased mental health and reported good sleep. In contrast, poor sleepers scored lower on the mental health index. High stress was more closely related to low mental health among poor sleepers. Most importantly, perceived fitness revealed a stress-buffering effect, but only among officers who reported good sleep. Conclusions: High perceived fitness and good sleep operate as stress resilience resources among police officers. The findings suggest that multimodal programs including stress management, sleep hygiene and fitness training are essential components of workplace health promotion in the police force