Optimization of a 3D dynamic culturing system for in vitro modeling of Frontotemporal Neurodegeneration-relevant pathologic features

Frontotemporal lobar degeneration (FTLD) is a severe neurodegenerative disorder that is diagnosed with increasing frequency in clinical setting. Currently, no therapy is available and in addition the molecular basis of the disease are far from being elucidated. Consequently, it is of pivotal importance to develop reliable and cost-effective in vitro models for basic research purposes and drug screening. To this respect, recent results in the field of Alzheimer’s disease have suggested that a tridimensional (3D) environment is an added value to better model key pathologic features of the disease. Here, we have tried to add complexity to the 3D cell culturing concept by using a microfluidic bioreactor, where cells are cultured under a continuous flow of medium, thus mimicking the interstitial fluid movement that actually perfuses the body tissues, including the brain. We have implemented this model using a neuronal-like cell line (SH-SY5Y), a widely exploited cell model for neurodegenerative disorders that shows some basic features relevant for FTLD modeling, such as the release of the FTLD-related protein progranulin (PRGN) in specific vesicles (exosomes). We have efficiently seeded the cells on 3D scaffolds, optimized a disease-relevant oxidative stress experiment (by targeting mitochondrial function that is one of the possible FTLD-involved pathological mechanisms) and evaluated cell metabolic activity in dynamic culture in comparison to static conditions, finding that SH-SY5Y cells cultured in 3D scaffold are susceptible to the oxidative damage triggered by a mitochondrial-targeting toxin (6-OHDA) and that the same cells cultured in dynamic conditions kept their basic capacity to secrete PRGN in exosomes once recovered from the bioreactor and plated in standard 2D conditions. We think that a further improvement of our microfluidic system may help in providing a full device where assessing basic FTLD-related features (including PRGN dynamic secretion) that may be useful for monitoring disease progression over time or evaluating therapeutic interventions

Load following of Small Modular Reactors (SMR) by cogeneration of hydrogen: A techno-economic analysis

Load following is the possibility for a power plant to adjust its power output according to the demand and electricity price fluctuation throughout the day. In nuclear power plants, the adjustment is usually done by inserting control rods into the reactor pressure vessel. This operation is inherently inefficient as nuclear power cost structure is composed almost entirely of sunk or fixed costs; therefore, lowering the power output, does not significantly reduce operating expenses and the plant is thermo-mechanical stressed. A more attractive option is to maintain the primary circuit at full power and use the excess power for cogeneration. This paper aims to present the techno-economic feasibility of nuclear power plants load following by cogenerating hydrogen. The paper assesses Small Modular nuclear Reactors (SMRs) coupled with: alkaline water electrolysis, high-temperature steam electrolysis, sulphur-iodine cycle. The analysis shows that in the medium term hydrogen from alkaline water electrolysis can be produced at competitive prices. High-temperature steam electrolysis and even more the sulphur-iodine cycle proved to be attractive because of their capability to produce hydrogen with higher efficiency. However, the coupling of SMRs and hydrogen facilities working at high temperature (about 800 °C) still requires substantial R&D to reach commercialisation

Exploring Alzheimer's disease mouse brain through X-ray phase contrast tomography: From the cell to the organ

Alzheimer's disease (AD), the most common form of dementia, is a progressive neurodegenerative disorder associated with aberrant production of beta-amyloid (A beta) peptide depositing in brain as amyloid plaques. While animal models allow investigation of disease progression and therapeutic efficacy, technology to fully dissect the pathological mechanisms of this complex disease at cellular and vascular levels is lacking.X-ray phase contrast tomography (XPCT) is an advanced non-destructive 3D multi-scale direct imaging from the cell through to the whole brain, with exceptional spatial and contrast resolution. We exploit XPCT to simultaneously analyse disease-relevant vascular and neuronal networks in AD mouse brain, without sectioning and staining. The findings clearly show the different typologies and internal structures of A beta plaques, together with their interaction with patho/physiological cellular and neuro-vascular microenvironment. XPCT enables for the first time a detailed visualization of amyloid-angiopathy at capillary level, which is impossible to achieve with other approaches.XPCT emerges as added-value technology to explore AD mouse brain as a whole, preserving tissue chemistry and structure, enabling the comparison of physiological vs. pathological states at the level of crucial disease targets. In-vivo translation will permit to monitor emerging therapeutic approaches and possibly shed new light on pathological mechanisms of neurodegenerative diseases

Modulation of Host Cell Apoptosis by <em>Trypanosoma cruzi</em>: Repercussions in the Development of Chronic Chagasic Cardiomyopathy

Trypanosoma cruzi is an intracellular parasite, which causes Chagas disease, affecting millions of people throughout the world. T. cruzi can invade several cell types, among which macrophages and cardiomyocytes stand out. Chagas disease goes through two stages: acute and chronic. If it becomes chronic, its most severe form is the chagasic chronic cardiomyopathy, which accounts for most of the fatalities due to this disease. For parasites to persist for long enough in cells, they should evade several host immune responses, one of these being apoptosis. Apoptosis is a type of programmed cell death described as a well-ordered and silent collection of steps that inevitably lead cells to a noninflammatory death. Cells respond to infection by initiating their own death to combat the infection. As a result, several intracellular microorganisms have developed different strategies to overcome host cell apoptosis and persist inside cells. It has been shown that T. cruzi has the ability to inhibit host cells apoptosis and can also induce apoptosis of cells that combat the parasite such as cytotoxic T cells. The aim of this chapter is to present up-to-date information about the molecules and mechanisms engaged by T. cruzi to achieve this goal and how the modulation of apoptosis by T. cruzi reflects in the development of chronic chagasic cardiomyopathy

Molecular beam epitaxy of CuMnAs

We present a detailed study of the growth of the tetragonal polymorph of antiferromagnetic CuMnAs by the molecular beam epitaxy technique. We explore the parameter space of growth conditions and their effect on the microstructural and transport properties of the material. We identify its typical structural defects and compare the properties of epitaxial CuMnAs layers grown on GaP, GaAs and Si substrates. Finally, we investigate the correlation between the crystalline quality of CuMnAs and its performance in terms of electrically induced resistance switching.Comment: 10 pages, 8 figures and supplementary materia

Low oxygen tension primes aortic endothelial cells to the reparative effect of tissue-protective cytokines

Erythropoietin (EPO) has both erythropoietic and tissue-protective properties. The EPO analogues carbamylated EPO (CEPO) and pyroglutamate helix B surface peptide (pHBSP) lack the erythropoietic activity of EPO but retain the tissue-protective properties that are mediated by a heterocomplex of EPO receptor (EPOR) and the β common receptor (βCR). We studied the action of EPO and its analogues in a model of wound healing where a bovine aortic endothelial cells (BAECs) monolayer was scratched and the scratch closure was assessed over 24 h under different oxygen concentrations. We related the effects of EPO and its analogues on repair to their effect on BAECs proliferation and migration (evaluated using a micro-Boyden chamber). EPO, CEPO and pHBSP enhanced scratch closure only at lower oxygen (5%), while their effect at atmospheric oxygen (21%) was not significant. The mRNA expression of EPOR was doubled in 5% compared to 21% oxygen, and this was associated with increased EPOR assessed by immunofluorescence and Western blot. By contrast βCR mRNA levels were similar in 5% and 21% oxygen. EPO and its analogues increased both BAECs proliferation and migration, suggesting that both may be involved in the reparative process. The priming effect of low oxygen tension on the action of tissue-protective cytokines may be of relevance to vascular disease, including atherogenesis and restenosis