The Relationship between Choline Bioavailability from Diet, Intestinal Microbiota Composition, and Its Modulation of Human Diseases

© 2020 by the authors.Choline is a water-soluble nutrient essential for human life. Gut microbial metabolism of choline results in the production of trimethylamine (TMA), which, upon absorption by the host is converted into trimethylamine-N-oxide (TMAO) in the liver. A high accumulation of both components is related to cardiovascular disease, inflammatory bowel disease, non-alcoholic fatty liver disease, and chronic kidney disease. However, the relationship between the microbiota production of these components and its impact on these diseases still remains unknown. In this review, we will address which microbes contribute to TMA production in the human gut, the extent to which host factors (e.g., the genotype) and diet affect TMA production, and the colonization of these microbes and the reversal of dysbiosis as a therapy for these diseases.This work was supported by the Ministry of Science, Innovation and Universities (PSI2017-83893-R to J.L.A.) and the Ministry of Economy and Business (PSI2015-73111-EXP to J.L.A., PSI2017-90806-REDT to J.L.A. and AGL2017-83653R to M.G.) (Spain). S.A. was the recipient of a postdoctoral Juan de la Cierva Contract (Ministry of Science, Innovation and Universities, Ref. IJCI-2017-32156).Peer reviewe

Dielectric Properties and Characterisation of Titanium Dioxide Obtained by Different Chemistry Methods

We made comparison of titanium dioxide powders obtained from three syntheses including sol-gel and precipitation methods as well as using layered (tetramethyl)ammonium titanate as a source of TiO2. The obtained precursors were subjected to step annealing at elevated temperatures to transform into rutile form. The transformation was determined by Raman measurements in each case. The resulting products were characterised using Raman spectroscopy and dynamic light scattering. The main goal of the studies performed was to compare the temperature of the transformation in three titania precursors obtained by different methods of soft chemistry routes and to evaluate dielectric properties of rutile products by means of broadband dielectric spectroscopy. Different factors affecting the electrical properties of calcinated products were discussed. It was found that sol-gel synthesis provided rutile form after annealing at 850°C with the smallest particles size about 20 nm, the highest value of dielectric permittivity equal to 63.7, and loss tangent equal to 0.051 at MHz frequencies. The other powders transformed to rutile at higher temperature, that is, 900°C, exhibit lower value of dielectric permittivity and had a higher value of particles size. The correlation between the anatase-rutile transformation temperature and the size of annealed particles was proposed.This work was financially supported by the National Science Center (Poland) grant awarded by Decision no. DEC-2011/03/D/ST5/06074. The authors are grateful to Professor Adam Tracz from the Polish Academy of Science in Lodz for his help in performing SEM investigations

Npas4 Expression in Two Experimental Models of the Barrel Cortex Plasticity

Npas4 has recently been identified as an important factor in brain plasticity, particularly in mechanisms of inhibitory control. Little is known about Npas4 expression in terms of cortical plasticity. In the present study expressions of Npas4 and the archetypal immediate early gene (IEG) c-Fos were investigated in the barrel cortex of mice after sensory deprivation (sparing one row of whiskers for 7 days) or sensory conditioning (pairing stimulation of one row of whiskers with aversive stimulus). Laser microdissection of individual barrel rows allowed for analysis of IEGs expression precisely in deprived and nondeprived barrels (in deprivation study) or stimulated and nonstimulated barrels (in conditioning study). Cortex activation by sensory conditioning was found to upregulate the expression of both Npas4 and c-Fos. Reorganization of cortical circuits triggered by removal of selected rows of whiskers strongly affected c-Fos but not Npas4 expression. We hypothesize that increased inhibitory synaptogenesis observed previously after conditioning may be mediated by Npas4 expression

Targeting DNA Methylation in the Adult Brain through Diet

Metabolism and nutrition have a significant role in epigenetic modifications such as DNA methylation, which can influence gene expression. Recently, it has been suggested that bioactive nutrients and gut microbiota can alter DNA methylation in the central nervous system (CNS) through the gut–brain axis, playing a crucial role in modulating CNS functions and, finally, behavior. Here, we will focus on the effect of metabolic signals in shaping brain DNA methylation during adulthood. We will provide an overview of potential interactions among diet, gastrointestinal microbiome and epigenetic alterations on brain methylation and behavior. In addition, the impact of different diet challenges on cytosine methylation dynamics in the adult brain will be discussed. Finally, we will explore new ways to modulate DNA hydroxymethylation, which is particularly abundant in neural tissue, through diet

Elucidating the Role of Cerebellar Synaptic Dysfunction in C9orf72-ALS/FTD — a Systematic Review and Meta-Analysis

A hexanucleotide repeat expansion in the C9orf72 gene is the most common genetic cause of amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD) with synaptic dysfunction identified as an early pathological hallmark. Although TDP-43 pathology and overt neurodegeneration are largely absent from the cerebellum, the pathological hallmarks of RNA foci and dipeptide repeat protein (DPR) inclusions are most abundant. Here, we present a systematic literature search in the databases of PubMed, Scopus, Embase, Web of Science and Science Direct up until March 5, 2021, which yielded 19,515 publications. Following the exclusion criteria, 72 articles were included having referred to C9orf72, synapses and the cerebellum. Meta-analyses were conducted on studies which reported experimental and control groups with means and standard deviations extracted from figures using the online tool PlotDigitizer. This revealed dendritic defects (P = 0.03), reduced C9orf72 in human patients (P = 0.005) and DPR-related neuronal loss (P = 0.0006) but no neuromuscular junction abnormalities (P = 0.29) or cerebellar neuronal loss (P = 0.23). Our results suggest that dendritic arborisation defects, synaptic gene dysregulation and altered synaptic neurotransmission may drive cerebellar synaptic dysfunction in C9-ALS/FTD. In this review, we discuss how the chronological appearance of the different pathological hallmarks alters synaptic integrity which may have profound implications for disease progression. We conclude that a reduction in C9orf72 protein levels combined with the accumulation of RNA foci and DPRs act synergistically to drive C9 synaptopathy in the cerebellum of C9-ALS/FTD patients

Paradoksalny efekt triangulacji?

Artykuł omawia wykorzystanie metody triangulacji w naukach społecznych. Triangulacja to strategia zwiększania rzetelności i trafności wyników badań. To zabieg metodologiczny mający na celu uwiarygodnienie zbieranych danych dzięki uwzględnieniu więcej niż dwóch ich źródeł. Polega na włączeniu różnych modeli i narzędzi pomiarowych do badania tego samego zjawiska. Autorki omawiają rolę triangulacji (szczególnie tzw. triangulacji danych) w naukach społecznych. Wskazują, że podstawowe nieporozumienie dotyczące triangulacji polega na oczekiwaniu, że różne metody będą dostarczały takich samych danych i będą prowadzić do takich samych rezultatów. Istoty triangulacji należy upatrywać nie tylko w możliwości zwiększania zaufania do otrzymanych wyników, ale przede wszystkim w możliwości głębszego zrozumienia badanego zjawiska i możliwości generowania nowych sposobów jego wyjaśniania

The Therapeutic Role of Exercise and Probiotics in Stressful Brain Conditions

Oxidative stress has been recognized as a contributing factor in aging and in the progression of multiple neurological disorders such as Parkinson’s disease, Alzheimer’s dementia, ischemic stroke, and head and spinal cord injury. The increased production of reactive oxygen species (ROS) has been associated with mitochondrial dysfunction, altered metal homeostasis, and compromised brain antioxidant defence. All these changes have been reported to directly affect synaptic activity and neurotransmission in neurons, leading to cognitive dysfunction. In this context two non-invasive strategies could be employed in an attempt to improve the aforementioned stressful brain status. In this regard, it has been shown that exercise could increase the resistance against oxidative stress, thus providing enhanced neuroprotection. Indeed, there is evidence suggesting that regular physical exercise diminishes BBB permeability as it reinforces antioxidative capacity, reduces oxidative stress, and has anti-inflammatory effects. However, the differential effects of different types of exercise (aerobic exhausted exercise, anaerobic exercise, or the combination of both types) and the duration of physical activity will be also addressed in this review as likely determinants of therapeutic efficacy. The second proposed strategy is related to the use of probiotics, which can also reduce some biomarkers of oxidative stress and inflammatory cytokines, although their underlying mechanisms of action remain unclear. Moreover, various probiotics produce neuroactive molecules that directly or indirectly impact signalling in the brain. In this review, we will discuss how physical activity can be incorporated as a component of therapeutic strategies in oxidative stress-based neurological disorders along with the augmentation of probiotics intake

Improvement of the solar cell efficiency by the ZnO nanoparticle layer via the down-shifting effect

International audienceA down-shifting material can generate one low-energy photon for every one incident high-energy photon. When such a material is placed on the front side of a photovoltaic solar cell, it has the potential to enhance the overall efficiency of the PV device by emitting photons in the spectral range where the solar cell efficiency is higher. This paper examines the application of ZnO nanoparticles as a luminescent down-shifting layer (LDSL) on the Si-based, CIGS and CdTe photovoltaic devices. The experimental results measured on a Si-based photovoltaic cell with a top luminescent down-shifting layer are analyzed. Theoretical solar cells performances were simulated using the SCAPS program. The elaborated electrical and optical models take into account the photoluminescence of the ZnO nanoparticle top layer. The obtained external quantum efficiency (EQE) and I–V characteristics were analyzed in order to estimate the impact of the photoluminescent down-shifting layer on the final efficiency of the Si, CIGS and CdTe solar cells. Contrary to the EQE curves, the I–V characteristics of the CIGS and CdTe solar cells are strongly affected by the presence of the photoluminescent down-shifting layer on their top