TY - JOUR A1 - Bhuvanesh, Thanga A1 - Machatschek, Rainhard Gabriel A1 - Lysyakova, Liudmila A1 - Kratz, Karl A1 - Schulz, Burkhard A1 - Ma, Nan A1 - Lendlein, Andreas T1 - Collagen type-IV Langmuir and Langmuir-Schafer layers as model biointerfaces to direct stem cell adhesion JF - Biomedical materials : materials for tissue engineering and regenerative medicine N2 - In biomaterial development, the design of material surfaces that mimic the extra-cellular matrix (ECM) in order to achieve favorable cellular instruction is rather challenging. Collagen-type IV (Col-IV), the major scaffolding component of Basement Membranes (BM), a specialized ECM with multiple biological functions, has the propensity to form networks by self-assembly and supports adhesion of cells such as endothelial cells or stem cells. The preparation of biomimetic Col-IV network-like layers to direct cell responses is difficult. We hypothesize that the morphology of the layer, and especially the density of the available adhesion sites, regulates the cellular adhesion to the layer. The Langmuir monolayer technique allows for preparation of thin layers with precisely controlled packing density at the air-water (A-W) interface. Transferring these layers onto cell culture substrates using the Langmuir-Schafer (LS) technique should therefore provide a pathway for preparation of BM mimicking layers with controlled cell adherence properties. In situ characterization using ellipsometry and polarization modulation-infrared reflection absorption spectroscopy of Col-IV layer during compression at the A-W interface reveal that there is linear increase of surface molecule concentration with negligible orientational changes up to a surface pressure of 25 mN m(-1). Smooth and homogeneous Col-IV network-like layers are successfully transferred by LS method at 15 mN m(-1) onto poly(ethylene terephthalate) (PET), which is a common substrate for cell culture. In contrast, the organization of Col-IV on PET prepared by the traditionally employed solution deposition method results in rather inhomogeneous layers with the appearance of aggregates and multilayers. Progressive increase in the number of early adherent mesenchymal stem cells (MSCs) after 24 h by controlling the areal Col-IV density by LS transfer at 10, 15 and 20 mN m(-1) on PET is shown. The LS method offers the possibility to control protein characteristics on biomaterial surfaces such as molecular density and thereby, modulate cell responses. KW - collagen-IV KW - basement membrane KW - Langmuir-Schafer films KW - stem cell adhesion KW - protein KW - ellipsometry Y1 - 2019 U6 - https://doi.org/10.1088/1748-605X/aaf464 SN - 1748-6041 SN - 1748-605X VL - 14 IS - 2 PB - Inst. of Physics Publ. CY - Bristol ER - TY - JOUR A1 - Eilers, Elisabeth Johanna A1 - Kleine, Sandra A1 - Eckert, Silvia A1 - Waldherr, Simon A1 - Müller, Caroline T1 - Flower production, headspace volatiles, pollen nutrients, and florivory in tanacetum vulgare chemotypes JF - Frontiers in plant science : FPLS N2 - Floral volatiles and reward traits are major drivers for the behavior of mutualistic as well as antagonistic flower visitors, i.e., pollinators and florivores. These floral traits differ tremendously between species, but intraspecific differences and their consequences on organism interactions remain largely unknown. Floral volatile compounds, such as terpenoids, function as cues to advertise rewards to pollinators, but should at the same time also repel florivores. The reward composition, e.g., protein and lipid contents in pollen, differs between individuals of distinct plant families. Whether the nutritional value of rewards within the same plant species is linked to their chemotypes, which differ in their pattern of specialized metabolites, has yet not been investigated. In the present study, we compared Tanacetum vulgare plants of five terpenoid chemotypes with regard to flower production, floral headspace volatiles, pollen macronutrient and terpenoid content, and floral attractiveness to florivorous beetles. Our analyses revealed remarkable differences between the chemotypes in the amount and diameter of flower heads, duration of bloom period, and pollen nutritional quality. The floral headspace composition of pollen-producing mature flowers, but not of premature flowers, was correlated to that of pollen and leaves in the same plant individual. For two chemotypes, florivorous beetles discriminated between the scent of mature and premature flower heads and preferred the latter. In semi-field experiments, the abundance of florivorous beetles and flower tissue miners differed between T. vulgare chemotypes. Moreover, the scent environment affected the choice and beetles were more abundant in homogenous plots composed of one single chemotype than in plots with different neighboring chemotypes. In conclusion, flower production, floral metabolic composition and pollen quality varied to a remarkable extend within the species T. vulgare, and the attractiveness of floral scent differed also intra-individually with floral ontogeny. We found evidence for a trade-off between pollen lipid content and pollen amount on a per-plant-level. Our study highlights that chemotypes which are more susceptible to florivory are less attacked when they grow in the neighborhood of other chemotypes and thus gain a benefit from high overall chemodiversity. KW - terpenoids KW - gas chromatography-mass spectrometry (GC-MS) KW - Asteraceae KW - protein KW - lipid-ratio KW - insect behavior KW - Phalacridae KW - chemodiversity Y1 - 2021 U6 - https://doi.org/10.3389/fpls.2020.611877 SN - 1664-462X VL - 11 PB - Frontiers Media CY - Lausanne ER - TY - JOUR A1 - Henze, Andrea A1 - Homann, Thomas A1 - Rohn, Isabelle A1 - Aschner, Michael A. A1 - Link, Christopher D. A1 - Kleuser, Burkhard A1 - Schweigert, Florian J. A1 - Schwerdtle, Tanja A1 - Bornhorst, Julia T1 - Caenorhabditis elegans as a model system to study post-translational modifications of human transthyretin JF - Scientific reports N2 - The visceral protein transthyretin (TTR) is frequently affected by oxidative post-translational protein modifications (PTPMs) in various diseases. Thus, better insight into structure-function relationships due to oxidative PTPMs of TTR should contribute to the understanding of pathophysiologic mechanisms. While the in vivo analysis of TTR in mammalian models is complex, time- and resource-consuming, transgenic Caenorhabditis elegans expressing hTTR provide an optimal model for the in vivo identification and characterization of drug-mediated oxidative PTPMs of hTTR by means of matrix assisted laser desorption/ionization – time of flight – mass spectrometry (MALDI-TOF-MS). Herein, we demonstrated that hTTR is expressed in all developmental stages of Caenorhabditis elegans, enabling the analysis of hTTR metabolism during the whole life-cycle. The suitability of the applied model was verified by exposing worms to D-penicillamine and menadione. Both drugs induced substantial changes in the oxidative PTPM pattern of hTTR. Additionally, for the first time a covalent binding of both drugs with hTTR was identified and verified by molecular modelling. KW - n-acetyl-cysteine KW - s-glutathionylation KW - force-field KW - c. elegans KW - life-span KW - protein KW - cells KW - menadione KW - disease KW - binding Y1 - 2016 U6 - https://doi.org/10.1038/srep37346 SN - 2045-2322 VL - 6 PB - Nature Publishing Group CY - London ER - TY - THES A1 - Herpich, Catrin T1 - Fibroblast growth factor 21 and its association with nutritional stimuli in older age N2 - Fibroblast growth differentiation factor 21 (FGF21) is known as a pivotal regulator of the glucose and lipid metabolism. As such, it is considered beneficial and has even been labelled a longevity hormone. Nevertheless, recent observational studies have shown that FGF21 is increased in higher age with possible negative effects such as loss of lean and bone mass as well as decreased survival. Hepatic FGF21 secretion can be induced by various nutritional stimuli such as starvation, high carbohydrate and fat intake as well as protein deficiency.. So far it is still unclear whether the FGF21 response to different macronutrients is altered in older age. An altered response would potentially contribute to explain the higher FGF21 concentrations found in older age. In this publication-based doctoral dissertation, a cross-sectional study as well as a dietary challenge were conducted to investigate the influence of nutrition on FGF21 concentrations and response in older age. In a cross-sectional study, FGF21 concentrations were assessed in older patients with and without cachexia anorexia syndrome anorexia syndrome compared to an older community-dwelling control group. Cachexia anorexia syndrome is a multifactorial syndrome frequently occurring in old age or in the context of an underlying disease. It is characterized by a severe involuntary weight loss, loss of appetite (anorexia) and reduced food intake, therefore representing a state of severe nutrient deficiency, in some aspects similar to starvation. The highest FGF21 concentrations were found in patients with cachexia anorexia syndrome. Moreover, FGF21 was positively correlated with weight loss and loss of appetite. In addition, cachexia anorexia syndrome itself was associated with FGF21 independent of sex, age and body mass index. As cachectic patients presumably exhibit protein malnutrition and FGF21 has been proposed a marker for protein insufficiency, the higher levels of FGF21 in patients with cachexia anorexia syndrome might be partly explained by insufficient protein intake. In order to investigate the acute response of FGF21 to different nutritional stimuli, a dietary challenge with a parallel group design was conducted. Here, healthy older (65-85 years) and younger (18-35 years) adults were randomized to one of four test meals: a dextrose drink, a high carbohydrate, high fat or high protein meal. Over the course of four hours, postprandial FGF21 concentrations (dynamics) were assessed and the FGF21 response (incremental area under the curve) to each test meal was examined.. In a sub-group of older and younger women, also the adiponectin response was investigated, as adiponectin is a known mediator of FGF21 effects on glucose and lipid metabolism. The dietary meal challenge revealed that dextrose and high carbohydrate intake result in higher FGF21 concentrations after four hours in older adults. This was partly explained by higher postprandial glucose concentrations in the old. For high fat ingestion no age differences were found. For the first time, acute FGF21 response to high protein intake was shown. Here, protein ingestion resulted in lower FGF21 concentrations in younger compared to older adults. Furthermore, sufficient protein intake, according to age-dependent recommendations, of the previous day, was associated with lower FGF21 concentrations in both age groups. The higher FGF21 response to dextrose ingestion resulted in a higher adiponectin response in older women, independent of fat mass, insulin resistance, triglyceride concentrations, inflammation and oxidative stress. Following the high fat meal, adiponectin concentrations declined in older women. Adiponectin response was not affected by meal composition in younger women. In summary, this thesis showed a positive association of FGF21 and cachexia anorexia syndrome with concomitant anorexia in older patients. Regarding the acute FGF21 response, a higher response following dextrose and carbohydrate ingestion was found in older compared with younger subjects. This might be attributed to a higher glucose response in older age. Furthermore, it was shown that the higher FGF21 response after dextrose ingestion possibly contributes to a higher adiponectin response in older women, independent of potential metabolic and inflammatory confounders. Acute protein ingestion resulted in a significant decrease in FGF21 concentrations. Moreover, protein intake of the previous day was inversely associated with fasting FGF21 concentrations. This might explain why FGF21 concentrations are higher in cachexia anorexia syndrome. These results therefore support the role of FGF21 as a sensor of protein restriction. N2 - Der Fibroblasten Wachstumsfaktor 21 (FGF21) gilt als wichtiger Regulator des Glukose- und Fettstoffwechsels. Es werden ihm verschiedene förderliche Eigenschaften zugeschrieben und er wurde darüber hinaus als Langlebigkeitshormon bezeichnet. Nichtsdestotrotz konnten Beobachtungsstudien zeigen, dass FGF21 Konzentration im Alter erhöht sind und möglicherweise mit negativen Auswirkungen, wie dem Verlust von Muskel- und Knochenmasse sowie einer geringeren Überlebenswahrscheinlichkeit, verbunden sind. FGF21 Sekretion in der Leber kann durch Hungern und verschiedene Makronährstoffe, wie hohe Kohlenhydrat- und Fettaufnahme, sowie einem Proteinmangel, induziert werden. Bisher ist jedoch unklar, ob sich die FGF21 Response auf verschiedene Makronährstoffe zwischen älteren und jüngeren Erwachsenen unterscheidet. Eine veränderte Response, könnte dazu beitragen die höheren FGF21 Konzentrationen im Alter zu erklären. In dieser vorliegenden kumulativen Dissertation wurden eine Querschnittsstudie sowie ein experimenteller Mahlzeitentest durchgeführt, um den Einfluss von Ernährung auf FGF21 Konzentrationen und die FGF21 Response im Alter zu untersuchen. In der Querschnittsstudie wurden FGF21 Konzentration von älteren PatientInnen mit und ohne Kachexie-Anorexie Syndrom sowie einer älteren Kontrollgruppe verglichen. Kachexie-Anorexie Syndrom ist ein multifaktorielles Syndrom, welches häufig im Alter und im Rahmen verschiedener Erkrankungen auftritt. Charakteristisch hierfür ist ein starker ungewollter Gewichtsverlust, Appetitverlust (Anorexie) sowie eine verminderte Nahrungsaufnahme. Daher repräsentiert das Kachexie-Anorexie Syndrom einen Zustand des schwerwiegenden Nährstoffmangels, der mit Unterernährung bei langanhaltenden Hungerphasen vergleichbar ist. Die höchsten FGF21 Konzentrationen wiesen PatientInnen mit Kachexie-Anorexie Syndrom auf. Des Weiteren korrelierte FGF21 positiv mit Gewichts- und Appetitverlust. Zusätzlich war das Kachexie-Anorexie Syndrom unabhängig von Alter, Geschlecht und BMI mit FGF21 assoziiert. Es ist davon auszugehen, dass PatientInnen mit Kachexie-Anorexie Syndrom eine unzureichende Proteinzufuhr aufweisen. Da FGF21 als Marker für Proteinrestriktion gilt, könnten die hohen FGF21 Konzentrationen bei Kachexie-Anorexie Syndrom teilweise durch eine zu geringe Proteinzufuhr erklärt werden. Um die akute Response von FGF21 auf verschiedene Makronährstoffe zu untersuchen, wurde ein Mahlzeitentest mit parallelen Gruppen durchgeführt. Hierfür erhielten ältere (65-85 Jahre) und jüngere (18-35 Jahre) Erwachsene eine von vier verschiedenen Testmahlzeiten (Dextrose Getränk, Kohlenhydrat-, Fett- und Proteinreiche Mahlzeit). Über vier Stunden wurden postprandiale FGF21 Konzentrationen (Dynamik) bestimmt und die FGF21 Response (inkrementelle Fläche unter der Kurve) auf jede Testmahlzeit untersucht. In einer Subgruppe von älteren und jüngeren Frauen wurde außerdem die Adiponektin Response bestimmt, da Adiponektin bekanntermaßen die Effekte von FGF21 auf den Glukose- und Fettstoffwechsel mediiert. Der Mahlzeitentest konnte zeigen, dass Dextrose und die kohlenhydratreiche Mahlzeit bei älteren Erwachsenen zu höheren FGF21 Konzentrationen nach vier Stunden führten. Dies könnte durch die höheren postprandialen Glukose Konzentrationen der Älteren erklärt werden. Die FGF21 Response auf die fettreiche Mahlzeit wies keine Altersunterschiede auf. Zum ersten Mal konnte die akute FGF21 Response auf eine proteinreiche Mahlzeit gezeigt werden. Hierbei führte die Mahlzeit bei jüngeren im Vergleich zu älteren Erwachsenen zu niedrigeren FGF21 Konzentration nach vier Stunden. Des Weiteren, war das Erreichen der altersspezifischen Proteinzufuhr des Vortrags bei beiden Altersgruppen mit niedrigeren nüchtern FGF21 Konzentrationen assoziiert. Bei älteren Frauen führte die höhere FGF21 Response nach Dextrose Aufnahme zu einer höheren Adiponektin Response, unabhängig von Fettmasse, Insulinresistenz, Triglyzeride Konzentrationen, Inflammation und oxidativem Stress. Nach Einnahme der fettreichen Mahlzeit sanken die Adiponektin Konzentrationen bei älteren Frauen, während bei jüngeren Frauen die Adiponektin Response nicht durch die Zusammensetzung der Mahlzeit beeinflusst wurde. Zusammenfassend konnte diese Dissertation eine positive Assoziation von FGF21 mit Kachexie-Anorexie Syndrom bei gleichzeitiger Anorexie bei älteren PatientInnen zeigen. Bezüglich der akuten Response von FGF21 zeigte sich eine höhere Response auf Dextrose und Kohlenhydrat-Aufnahme bei älteren im Vergleich zu jüngeren ProbandInnen. Dies ist vermutlich auf die erhöhte Glukose Response im Alter zurückzuführen. Des Weiteren konnte gezeigt werden, dass eine höhere FGF21 Response auf Dextrose bei älteren Frauen mit einer veränderten Adiponektin Response einhergingen, unabhängig von potentiellen metabolischen und inflammatorischen Einflussfaktoren. Eine akute hohe Proteinaufnahme führte zu einem deutlichen Abfall der postprandialen FGF21 Konzentrationen. Zudem bestand eine inverse Assoziation zwischen FGF21 Nüchternkonzentrationen und der Proteinzufuhr des Vortags. Dies könnte zum Teil erklären, warum FGF21 Konzentrationen bei Kachexie-Anorexie Syndrom erhöht sind. Demnach unterstützen diese Ergebnisse auch die Rolle von FGF21 als Sensor für Proteinrestriktion. KW - Ageing KW - FGF21 KW - protein KW - postprandial response Y1 - 2021 ER - TY - JOUR A1 - Hoie, Lars H. A1 - Sjoholm, Ake A1 - Guldstrand, Marie A1 - Zunft, Hans-Joachim Franz A1 - Lueder, Wolfgang A1 - Graubaum, Hans-Joachim A1 - Grünwald, Jörg T1 - Ultra heat treatment destroys cholesterol-lowering effect of soy protein JF - International journal of food sciences and nutrition N2 - A randomized, placebo-controlled, double-blind clinical study was performed to investigate the dose-dependent response of serum cholesterol after consuming an ultra-heat-treated milk containing a soy protein preparation. Eighty hypercholesterolemic subjects were assigned to one of four study groups receiving 12.5 or 25 g soy protein (active treatment) or casein (placebo) daily over a period of 4 weeks. The trial substances were provided as ready-made, ultra-heated milk preparations. Before and after the treatment, serum concentrations of total, low-density lipoprotein, and high-density lipoprotein cholesterol were determined. Unexpectedly, at the end of the study, low-density lipoprotein cholesterol concentrations were significantly increased compared with baseline in all study groups. The magnitude of this increase (17 - 19%) was similar in all active and placebo study groups. Soy protein supplements previously shown to be effective in reducing serum cholesterol had in this study no such lipid-lowering effect after ultra heat treatment. KW - soy KW - protein KW - cholesterol KW - ultra heat treatment Y1 - 2006 U6 - https://doi.org/10.1080/09637480601009059 SN - 0963-7486 VL - 57 SP - 512 EP - 519 PB - Taylor & Francis CY - Abingdon ER - TY - JOUR A1 - Laux, Eva-Maria A1 - Ermilova, Elena A1 - Pannwitz, Daniel A1 - Gibbons, Jessica A1 - Hölzel, Ralph A1 - Bier, Frank Fabian T1 - Dielectric Spectroscopy of Biomolecules up to 110 GHz JF - Frequenz N2 - Radio-frequency fields in the GHz range are increasingly applied in biotechnology and medicine. In order to fully exploit both their potential and their risks detailed information about the dielectric properties of biological material is needed. For this purpose a measuring system is presented that allows the acquisition of complex dielectric spectra over 4 frequency decade up to 110 GHz. Routines for calibration and for data evaluation according to physicochemical interaction models have been developed. The frequency dependent permittivity and dielectric loss of some proteins and nucleic acids, the main classes of biomolecules, and of their sub-units have been determined. Dielectric spectra are presented for the amino acid alanine, the proteins lysozyme and haemoglobin, the nucleotides AMP and ATP, and for the plasmid pET-21, which has been produced by bacterial culture. Characterisation of a variety of biomolecules is envisaged, as is the application to studies on protein structure and function. KW - dielectric KW - spectroscopy KW - permittivity KW - protein KW - DNA KW - amino acid KW - plasmid Y1 - 2018 U6 - https://doi.org/10.1515/freq-2018-0010 SN - 0016-1136 SN - 2191-6349 VL - 72 IS - 3-4 SP - 135 EP - 140 PB - De Gruyter CY - Berlin ER - TY - JOUR A1 - Lämke, Jörn A1 - Bäurle, Isabel T1 - Epigenetic and chromatin-based mechanisms in environmental stress adaptation and stress memory in plants JF - Genome biology : biology for the post-genomic era N2 - Plants frequently have to weather both biotic and abiotic stressors, and have evolved sophisticated adaptation and defense mechanisms. In recent years, chromatin modifications, nucleosome positioning, and DNA methylation have been recognized as important components in these adaptations. Given their potential epigenetic nature, such modifications may provide a mechanistic basis for a stress memory, enabling plants to respond more efficiently to recurring stress or even to prepare their offspring for potential future assaults. In this review, we discuss both the involvement of chromatin in stress responses and the current evidence on somatic, intergenerational, and transgenerational stress memory. KW - remodeling atpase brahma KW - transcriptional memory KW - DNA methylation KW - transgenerational inheritance KW - acquired thermotolerance KW - Arabidopsis-thaliana KW - gene-expression KW - responses KW - protein KW - defense Y1 - 2017 U6 - https://doi.org/10.1186/s13059-017-1263-6 SN - 1474-760X VL - 18 SP - 8685 EP - 8693 PB - BioMed Central CY - London ER - TY - JOUR A1 - Schweigert, Florian J. A1 - Gericke, Beate A1 - Wolfram, Wiebke A1 - Kaisers, Udo A1 - Dudenhausen, Joachim W. T1 - Peptide and protein profiles in serum and follicular fluid of women undergoing IVF JF - Human reproduction N2 - BACKGROUND: Proteins and peptides in human follicular fluid originate from plasma or are produced by follicular structures. Compositional changes reflect oocyte maturation and can be used as diagnostic markers. The aim of the study was to determine protein and peptide profiles in paired serum and follicular fluid samples from women undergoing IVF. METHODS: Surface-enhanced laser desorption and ionization-time of flight-mass spectrometry (SELDI-TOF-MS) was used to obtain characteristic protein pattern. RESULTS: One hundred and eighty-six individual MS signals were obtained from a combination of enrichment on strong anion exchanger (110), weak cation exchanger (52) and normal phase surfaces (24). On the basis of molecular masses, isoelectric points and immunoreactivety, four signals were identified as haptoglobin (alpha(1)- and alpha(2)-chain), haptoglobin 1 and transthyretin (TTR). Immunological and MS characteristics of the TTR : retinol-binding protein (RBP) transport complex revealed no microheterogeneity differences between serum and follicular fluid. Discriminatory patterns arising from decision-tree-based classification and regression analysis distinguished between serum and follicular fluid with a sensitivity and specificity of 100%. CONCLUSIONS: Quantitative and qualitative differences indicate selective transport processes rather than mere filtration across the blood-follicle barrier. Identified proteins as well as characteristic peptide and/or protein signatures might emerge as potential candidates for diagnostic markers of follicle and/or oocyte maturation and thus oocyte quality. KW - human follicular fluid KW - peptide KW - protein KW - proteome KW - serum Y1 - 2006 U6 - https://doi.org/10.1093/humrep/del257 SN - 0268-1161 VL - 21 IS - 11 SP - 2960 EP - 2968 PB - Univ. Press CY - Oxford ER -