Biopurification using non-growing microorganisms to improve plant protein ingredients.

Securing a sustainable global food supply for a growing population requires a shift toward a more plant-based diet. The application of plant-based proteins is therefore increasing, but unpleasant off-flavors complicate their use. Here, we screened 97 microorganisms for their potential to remove off-flavors in a process with limiting amounts of fermentable sugar.

The TNFR1 antagonist Atrosimab reduces neuronal loss, glial activation and memory deficits in an acute mouse model of neurodegeneration.

Tumor necrosis factor alpha (TNF-α) and its key role in modulating immune responses has been widely recognized as a therapeutic target for inflammatory and neurodegenerative diseases. Even though inhibition of TNF-α is beneficial for the treatment of certain inflammatory diseases, total neutralization of TNF-α largely failed in the treatment of neurodegenerative diseases. TNF-α exerts distinct functions depending on interaction with its two TNF receptors, whereby TNF receptor 1 (TNFR1) is associated with neuroinflammation and apoptosis and TNF receptor 2 (TNFR2) with neuroprotection and immune regulation.

Robust Tissue Fabrication for Long-Term Culture of iPSC-Derived Brain Organoids for Aging Research.

The currently available animal and cellular models do not fully recapitulate the complexity of changes that take place in the aging human brain. A recent development of procedures describing the generation of human cerebral organoids, derived from human induced pluripotent stem cells (iPSCs), has the potential to fundamentally transform the ability to model and understand the aging of the human brain and related pathogenic processes. Here, an optimized protocol for generating, maintaining, aging, and characterizing human iPSC-derived cerebral organoids is presented.

Alzheimer's Disease: Treatment Strategies and Their Limitations.

Alzheimer's disease (AD) is the most frequent case of neurodegenerative disease and is becoming a major public health problem all over the world. Many therapeutic strategies have been explored for several decades; however, there is still no curative treatment, and the priority remains prevention. In this review, we present an update on the clinical and physiological phase of the AD spectrum, modifiable and non-modifiable risk factors for AD treatment with a focus on prevention strategies, then research models used in AD, followed by a discussion of treatment limitations.

Use of standard U-bottom and V-bottom well plates to generate neuroepithelial embryoid bodies.

The use of organoids has become increasingly popular recently due to their self-organizing abilities, which facilitate developmental and disease modeling. Various methods have been described to create embryoid bodies (EBs) generated from embryonic or pluripotent stem cells but with varying levels of differentiation success and producing organoids of variable size. Commercial ultra-low attachment (ULA) V-bottom well plates are frequently used to generate EBs.

Engineering Organoids for Modeling of Phenylketonuria.

Phenylketonuria is a recessive genetic disorder of amino-acid metabolism, where impaired phenylalanine hydroxylase function leads to the accumulation of neurotoxic phenylalanine levels in the brain. Severe cognitive and neuronal impairment are observed in untreated/late-diagnosed patients, and even early treated ones are not safe from life-long sequelae. Despite the wealth of knowledge acquired from available disease models, the chronic effect of Phenylketonuria in the brain is still poorly understood and the consequences to the aging brain remain an open question.

A Review of Oxidative Stress Products and Related Genes in Early Alzheimer's Disease.

Oxidative stress is associated with the progression of Alzheimer's disease (AD). Reactive oxygen species can modify lipids, DNA, RNA, and proteins in the brain. The products of their peroxidation and oxidation are readily detectable at incipient stages of disease.

Cross-seeding of alpha-synuclein aggregation by amyloid fibrils of food proteins.

The aggregation of the protein α-synuclein (aSyn) into amyloid fibrils in the human brain is associated with the development of several neurodegenerative diseases, including Parkinson's disease. The previously observed prion-like spreading of aSyn aggregation throughout the brain and the finding that heterologous cross-seeding of amyloid aggregation occurs in vitro for some proteins suggest that exposure to amyloids in general may pose a risk for disease development. To elucidate which protein fibril characteristics determine if and how heterologous amyloid seeding can occur, we investigated the potential of amyloid fibrils formed from proteins found in food, hen egg white lysozyme, and bovine milk β-lactoglobulin to cross-seed aSyn aggregation in the test tube.

Plant isoquinoline alkaloids as potential neurodrugs: A comparative study of the effects of benzo[c]phenanthridine and berberine-based compounds on β-amyloid aggregation.

Herein we present a comparative study of the effects of isoquinoline alkaloids belonging to benzo[c]phenanthridine and berberine families on β-amyloid aggregation. Results obtained using a Thioflavine T (ThT) fluorescence assay and circular dichroism (CD) spectroscopy suggested that the benzo[c]phenanthridine nucleus, present in both sanguinarine and chelerythrine molecules, was directly involved in an inhibitory effect of Aβ aggregation. Conversely, coralyne, that contains the isomeric berberine nucleus, significantly increased propensity for Aβ to aggregate.

Milk Processing Affects Structure, Bioavailability and Immunogenicity of β-lactoglobulin.

Bovine milk is subjected to various processing steps to warrant constant quality and consumer safety. One of these steps is pasteurization, which involves the exposure of liquid milk to a high temperature for a limited amount of time. While such heating effectively ameliorates consumer safety concerns mediated by pathogenic bacteria, these conditions also have an impact on one of the main nutritional whey constituents of milk, the protein β-lactoglobulin.

Exposure of a cryptic Hsp70 binding site determines the cytotoxicity of the ALS-associated SOD1-mutant A4V.

The accumulation of toxic protein aggregates is thought to play a key role in a range of degenerative pathologies, but it remains unclear why aggregation of polypeptides into non-native assemblies is toxic and why cellular clearance pathways offer ineffective protection. We here study the A4V mutant of SOD1, which forms toxic aggregates in motor neurons of patients with familial amyotrophic lateral sclerosis (ALS). A comparison of the location of aggregation prone regions (APRs) and Hsp70 binding sites in the denatured state of SOD1 reveals that ALS-associated mutations promote exposure of the APRs more than the strongest Hsc/Hsp70 binding site that we could detect.

Molecular Mechanisms and Genetics of Oxidative Stress in Alzheimer's Disease.

Alzheimer's disease is the most common neurodegenerative disorder that can cause dementia in elderly over 60 years of age. One of the disease hallmarks is oxidative stress which interconnects with other processes such as amyloid-β deposition, tau hyperphosphorylation, and tangle formation. This review discusses current thoughts on molecular mechanisms that may relate oxidative stress to Alzheimer's disease and identifies genetic factors observed from in vitro, in vivo, and clinical studies that may be associated with Alzheimer's disease-related oxidative stress.

Apolipoprotein E associated with reconstituted high-density lipoprotein-like particles is protected from aggregation.

Apolipoprotein E (APOE) genotype determines Alzheimer's disease (AD) susceptibility, with the APOE ε4 allele being an established risk factor for late-onset AD. The ApoE lipidation status has been reported to impact amyloid-beta (Aβ) peptide metabolism. The details of how lipidation affects ApoE behavior remain to be elucidated.

Benzodifurans for biomedical applications: BZ4, a selective anti-proliferative and anti-amyloid lead compound.

Our goal is to evaluate benzodifuran-based scaffolds for biomedical applications. We here explored the anticancer and anti-amyloid activities of a novel compound (BZ4) in comparison with other known benzodifuran analogs, previously studied in our group, and we have explored its ability to interact with different DNA model systems. BZ4 shows antiproliferative activity on different cancer cells; does not affect noncancerous control cells and alters the aggregation properties of β-amyloid, as ascertained by circular dichroism, fluorescence spectroscopy and scanning electron microscopy analysis.

Searching for improved mimetic peptides inhibitors preventing conformational transition of amyloid-β monomer.

A series of novel mimetic peptides were designed, synthesised and biologically evaluated as inhibitors of Aβ aggregation. One of the synthesised peptidic compounds, termed compound 7 modulated Aβ aggregation as demonstrated by thioflavin T fluorescence, acting also as an inhibitor of the cytotoxicity exerted by Aβ aggregates. The early stage interaction between compound 7 and the Aβ monomer was investigated by replica exchange molecular dynamics (REMD) simulations and docking studies.

Structural and Aggregation Properties of Alpha-Synuclein Linked to Phospholipase A2 Action.

Background: Alpha-synuclein is a protein involved in the pathogenesis of Parkinson's disease. In vitro observations have shown that specific brain-enriched polyunsaturated fatty acids, such as arachidonic acid, can give rise to a conformational change in alpha-synuclein and ultimately induce its fibrillation. Arachidonic acid is released by phospholipase A2 activity and clinical observations have shown a link between mutations in PLA2G6, the gene responsible for the production of phospholipase A2, and early-onset types of parkinsonism.

The influence of N-terminal acetylation on micelle-induced conformational changes and aggregation of α-Synuclein.

The biological function of α-Synuclein has been related to binding to lipids and membranes but these interactions can also mediate α-Synuclein aggregation, which is associated to Parkinson's disease and other neuropathologies. In brain tissue α-Synuclein is constitutively N-acetylated, a modification that plays an important role in its conformational propensity, lipid and membrane binding, and aggregation propensity. We studied the interactions of the lipid-mimetic SDS with N-acetylated and non-acetylated α-Synuclein, as well as their early-onset Parkinson's disease variants A30P, E46K and A53T.

Optimized Triton X-114 assisted lipopolysaccharide (LPS) removal method reveals the immunomodulatory effect of food proteins.

Scope: Investigations into the immunological response of proteins is often masked by lipopolysaccharide (LPS) contamination. We report an optimized Triton X-114 (TX-114) based LPS extraction method for β-lactoglobulin (BLG) and soy protein extract suitable for cell-based immunological assays.

Methods And Results: Optimization of an existing TX-114 based phase LPS extraction method resulted in >99% reduction of LPS levels.

Characterization of insulin-degrading enzyme-mediated cleavage of Aβ in distinct aggregation states.

To enhance our understanding of the potential therapeutic utility of insulin-degrading enzyme (IDE) in Alzheimer's disease (AD), we studied in vitro IDE-mediated degradation of different amyloid-beta (Aβ) peptide aggregation states. Our findings show that IDE activity is driven by the dynamic equilibrium between Aβ monomers and higher ordered aggregates. We identify Met(35)-Val(36) as a novel IDE cleavage site in the Aβ sequence and show that Aβ fragments resulting from IDE cleavage form non-toxic amorphous aggregates.

Could ecosystem management provide a new framework for Alzheimer's disease?

Alzheimer's disease (AD) is a progressive neurodegenerative brain disorder that involves a plethora of molecular pathways. In the context of therapeutic treatment and biomarker profiling, the amyloid-beta (Aβ) peptide constitutes an interesting research avenue that involves interactions within a complex mixture of Aβ alloforms and other disease-modifying factors. Here, we explore the potential of an ecosystem paradigm as a novel way to consider AD and Aβ dynamics in particular.

Two distinct β-sheet structures in Italian-mutant amyloid-beta fibrils: a potential link to different clinical phenotypes.

Most Alzheimer's disease (AD) cases are late-onset and characterized by the aggregation and deposition of the amyloid-beta (Aβ) peptide in extracellular plaques in the brain. However, a few rare and hereditary Aβ mutations, such as the Italian Glu22-to-Lys (E22K) mutation, guarantee the development of early-onset familial AD. This type of AD is associated with a younger age at disease onset, increased β-amyloid accumulation, and Aβ deposition in cerebral blood vessel walls, giving rise to cerebral amyloid angiopathy (CAA).

New mimetic peptides inhibitors of Αβ aggregation. Molecular guidance for rational drug design.

A new series of mimetic peptides possessing a significant Aβ aggregation modulating effect was reported here. These compounds were obtained based on a molecular modelling study which allowed us to perform a structural-based virtual selection. Monitoring Aβ aggregation by thioflavin T fluorescence and transmission electron microscopy revealed that fibril formation was significantly decreased upon prolonged incubation in presence of the active compounds.

Mechanistic insights in glycation-induced protein aggregation.

Protein glycation causes loss-of-function through a process that has been associated with several diabetic-related diseases. Additionally, glycation has been hypothesized as a promoter of protein aggregation, which could explain the observed link between hyperglycaemia and the development of several aggregating diseases. Despite its relevance in a range of diseases, the mechanism through which glycation induces aggregation remains unknown.

Modulation of the gelation efficiency of fibrillar and spherical aggregates by means of thiolation.

Fibrillar and spherical aggregates were prepared from whey protein isolate (WPI). These aggregates were thiolated to a substantial degree to observe any impact on functionality. Sulfur-containing groups were introduced on these aggregates which could be converted to thiol groups by deblocking.

A comparative analysis of the aggregation behavior of amyloid-β peptide variants.

Aggregated forms of the amyloid-β peptide are hypothesized to act as the prime toxic agents in Alzheimer disease (AD). The in vivo amyloid-β peptide pool consists of both C- and N-terminally truncated or mutated peptides, and the composition thereof significantly determines AD risk. Other variations, such as biotinylation, are introduced as molecular tools to aid the understanding of disease mechanisms.