Elucidating the early events of protein aggregation using biophysical techniques

Proteins and peptides can convert from their native form into insoluble highly ordered fibrillar aggregates, known as amyloid fibrils. The process of fibrillogenesis is implicated in the pathogenic mechanisms of many diseases and, although mature fibrils are well characterised by a plethora of biophysical techniques, the initiation and early steps remain, to date, ambiguous. Mass spectrometry can provide invaluable insights into these early events as it can identify the low populated and transient oligomeric species present in the lag phase by their mass to charge ratio. Recent evidence has shown that oligomers formed early in the aggregation process are cytotoxic and may additionally be central to the progression of diseases associated with amyloid fibril presence. The hybrid technique of ion mobility mass spectrometry can be employed to provide conformational details of monomeric and multimeric species present and elucidate the presence of oligomers which possess coincident mass to charge ratios. Molecular modelling, in conjunction with experimental results, can suggest probable monomeric and oligomeric structural arrangements. In this thesis three aggregating systems are investigated: amyloidogenic transthyretin fragment (105-115), insulin and two Aβ peptides. Initially amyloidogenic endecapeptide transthyretin (105-115) is studied as it has been widely utilised as a model system for investigating amyloid formation due to its small size. Secondly insulin, a key hormone in metabolic processes, is investigated as extensive research has been carried out into its aggregation into amyloid fibrils. The formation of insulin amyloid fibrils rarely occurs in vivo; however localised amyloidosis at the site of injection and the aggregation of pharmaceutical insulin stocks present problems. Thirdly the aggregation of A β peptides Aβ (1-40) and Aβ (1-42) and their interactions with an aggregation inhibitor, RI-OR2, are characterised. A (1-42), although less commonly produced in vivo, is more cytotoxic and has a faster aggregation mechanism than Aβ (1-40). Both Aβ peptides are implicated in the aetiology of Alzheimer’s disease whilst RI-OR2 has been reported to prevent the production of high molecular weight oligomers, with particular suppression of Aβ (1-42) aggregation

Cell density monitoring and control of microencapsulated CHO cell cultures

Though mammalian cells play a key role in the manufacturing of recombinant glycosylated proteins, cell cultures and productivity are limited by the lack of suitable systems to enable stable perfusion culture. Microencapsulation, or entrapping cells within a semi-permeable membrane, offers the potential to generate high cell density cultures and improve the productivity by mimicking the cells natural environment. However, the cells being secluded by the microcapsules membrane are difficult to access for monitoring purposes. In this study, CHO-DP12 cells were cultured within calcium-alginate-poly-Llysine-alginate microcapsules in two bench scale- bioreactors, including a highly sensitive bench-scale calorimeter. The different cultures were monitored by continuous real-time dielectric spectroscopy and/or heat-flow measurements. These measurements were acquired, saved and plotted as time charts for rapid culture evaluation within a LabVIEW Virtual Instrument specifically designed for this study. Findings of this study show that capacitance measurements gave real time information on the viable cell density evolution in batch, fed batch and high density perfusion cultures; and the heat flux measurements allowed to follow the cell evolution in high density perfusion cultures. More significantly, dielectric spectroscopy gave precise information throughout each stage of the culture, from inoculation to the maximum cell density reached and through the early stages of the decline phase. Based on these results, a control strategy was implemented within the tailored LabVIEW program to control the feed rate of fed-batch cultures. The feed rate was calculated directly in the Virtual Instrument in accordance with the viable cell density and growth rate measured by dielectric spectroscopy. The capability of monitoring the evolution of microencapsulated cultures brings microencapsulation technology a step towards a potential industrial application

Developing a common R&I agenda and action plan

This poster highlights 32 Alliances’ examples on best practices and outcomes of their R&I projects, organized around the seven transformational modules. All the Alliances’ results are linked within the poster and can be accessed at once. In addition, a contact list regarding the R&I dimension of these Alliances is also included.This project has received funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement No 10101722

Marine regime shifts in ocean biogeochemical models:a case study in the Gulf of Alaska

Regime shifts have been reported in many marine ecosystems, and are often expressed as an abrupt change occurring in multiple physical and biological components of the system. In the Gulf of Alaska, a regime shift in the late 1970s was observed, indicated by an abrupt increase in sea surface temperature and major shifts in the catch of many fish species. A thorough understanding of the extent and mechanisms leading to such regime shifts is challenged by data paucity in time and space. We investigate the ability of a suite of ocean biogeochemistry models of varying complexity to simulate regime shifts in the Gulf of Alaska by examining the presence of abrupt changes in time series of physical variables (sea surface temperature and mixed-layer depth), nutrients and biological variables (chlorophyll, primary productivity and plankton biomass) using change-point analysis. Our results show that some ocean biogeochemical models are capable of simulating the late 1970s shift, manifested as an abrupt increase in sea surface temperature followed by an abrupt decrease in nutrients and biological productivity. Models from low to intermediate complexity simulate an abrupt transition in the late 1970s (i.e. a significant shift from one year to the next) while the transition is smoother in higher complexity models. Our study demonstrates that ocean biogeochemical models can successfully simulate regime shifts in the Gulf of Alaska region. These models can therefore be considered useful tools to enhance our understanding of how changes in physical conditions are propagated from lower to upper trophic levels

Detection of climate change-driven trends in phytoplankton phenology

The timing of the annual phytoplankton spring bloom is likely to be altered in response to climate change. Quantifying that response has, however, been limited by the typically coarse temporal resolution (monthly) of global climate models. Here, we use higher resolution model output (maximum 5 days) to investigate how phytoplankton bloom timing changes in response to projected 21st century climate change, and how the temporal resolution of data influences the detection of long-term trends. We find that bloom timing generally shifts later at mid-latitudes and earlier at high and low latitudes by ~5 days per decade to 2100. The spatial patterns of bloom timing are similar in both low (monthly) and high (5 day) resolution data, although initiation dates are later at low resolution. The magnitude of the trends in bloom timing from 2006 to 2100 is very similar at high and low resolution, with the result that the number of years of data needed to detect a trend in phytoplankton phenology is relatively insensitive to data temporal resolution. We also investigate the influence of spatial scales on bloom timing and find that trends are generally more rapidly detectable after spatial averaging of data. Our results suggest that, if pinpointing the start date of the spring bloom is the priority, the highest possible temporal resolution data should be used. However, if the priority is detecting long-term trends in bloom timing, data at a temporal resolution of 20 days are likely to be sufficient. Furthermore, our results suggest that data sources which allow for spatial averaging will promote more rapid trend detection

The Iowa Homemaker vol.33, no.4

An American Task, Dr. Paul Sharp, page 7 Pizza, Doris Jirsa, page 8 International Social Whirl, Ann Lindemeyer, page 9 Enchanting Paris, Else Nielsen, page 10 New Foods and Flavors, Dorothy Will, page 11 Costa Rican Friendships, Margaret Cole, page 12 A Debt Is Due, Marilyn Heu and Lillian Nakamota, page 13 Information Please, Rachel Bernau and Margaret Mattison, page 14 Overseas Jobs for YOU, Kay Scholten, page 15 Food for the Male, Pat Stiff, page 16 An Invitation to the U. N. Tea, Jane Hammerly, page 17 A.H.E.A. Ambassadors, Harriet Parsons, page 18 Nationally Speaking, Dorothy Will, page 19 What’s New, page 20 Trends, Gwen Owen, page 2

IDOL regulates systemic energy balance through control of neuronal VLDLR expression.

Liver X receptors limit cellular lipid uptake by stimulating the transcription of Inducible Degrader of the LDL Receptor (IDOL), an E3 ubiquitin ligase that targets lipoprotein receptors for degradation. The function of IDOL in systemic metabolism is incompletely understood. Here we show that loss of IDOL in mice protects against the development of diet-induced obesity and metabolic dysfunction by altering food intake and thermogenesis. Unexpectedly, analysis of tissue-specific knockout mice revealed that IDOL affects energy balance, not through its actions in peripheral metabolic tissues (liver, adipose, endothelium, intestine, skeletal muscle), but by controlling lipoprotein receptor abundance in neurons. Single-cell RNA sequencing of the hypothalamus demonstrated that IDOL deletion altered gene expression linked to control of metabolism. Finally, we identify VLDLR rather than LDLR as the primary mediator of IDOL effects on energy balance. These studies identify a role for the neuronal IDOL-VLDLR pathway in metabolic homeostasis and diet-induced obesity

Enhanced Avidity Maturation of Antibody to Human Immunodeficiency Virus Envelope: DNA Vaccination with gp120-C3d Fusion Proteins

DNA vaccination can elicit both humoral and cellular immune responses and can confer protection against several pathogens. However, DNA vaccines expressing the envelope (Env) protein of human immunodeficiency virus (HIV) have been relatively ineffective at generating high titer, long-lasting, neutralizing antibodies in a variety of animal models. In this study, we report that fusion of Env and the complement component, C3d, in a DNA vaccine, enhances the titers of antibody to Env. Plasmids were generated that expressed a secreted form of Env (sgp120) from three isolates of HIV and these same forms fused to three tandem copies of the murine homologue of C3d (sgp120-3C3d). Analyses of titers and avidity maturation of the raised antibody indicated that immunizations with each of the sgp120-3C3d-expressing DNAs accelerated both the onset and the avidity maturation of antibody to Env. Originally published AIDS Research and Human Retroviruses, Vol. 17, No. 9, June 200

Examining evidence for behavioural mimicry of parental eating by adolescent females.:An observational study

Behavioural mimicry is a potential mechanism explaining why adolescents appear to be influenced by their parents' eating behaviour. In the current study we examined whether there is evidence that adolescent females mimic their parents when eating. Videos of thirty-eight parent and female adolescent dyads eating a lunchtime meal together were examined. We tested whether a parent placing a food item into their mouth was associated with an increased likelihood that their adolescent child would place any food item (non-specific mimicry) or the same item (specific mimicry) in their mouth at three different time frames, namely, during the same second or within the next fifteen seconds (+15), five seconds (+5) or two second (+2) period. Parents and adolescents' overall food intake was positively correlated, whereby a parent eating a larger amount of food was associated with the adolescent eating a larger meal. Across all of the three time frames adolescents were more likely to place a food item in their mouth if their parent had recently placed that same food item in their mouth (specific food item mimicry); however, there was no evidence of non-specific mimicry. This observational study suggests that when eating in a social context there is evidence that adolescent females may mimic their parental eating behaviour, selecting and eating more of a food item if their parent has just started to eat that food