Influence of Estrogen Modulation on Glia Activation in a Murine Model of Parkinson's Disease

Epidemiological data suggest a sexual dimorphism in Parkinson disease (PD), with women showing lower risk of developing PD. Vulnerability of the nigrostriatal pathway may be influenced by exposure to estrogenic stimulation throughout fertile life. To further address this issue, we analyzed the progression of nigrostriatal damage, microglia and astrocyte activation and microglia polarization triggered by intrastriatal injection of dopaminergic neurotoxin 6-hydroxydopamine (6-OHDA) in male, female and ovariectomized (OVX) mice, as well as in OVX mice supplemented with 17\u3b2estradiol (OVX+E). Animals were sacrificed at different time points following 6-OHDA injection and brain sections containing striatum and substantia nigra pars compacta (SNc) underwent immunohistochemistry for tyrosine hydroxylase (TH) (dopaminergic marker), immunofluorescence for IBA1 and GFAP (markers of microglia and astrocyte activation, respectively) and triple immunoflorescent to identify polarization of microglia toward the cytotoxic M1 (DAPI/IBA1/TNF\u3b1) or cytoprotective M2 (DAPI/IBA1/CD206) phenotype. SNc damage induced by 6-OHDA was significantly higher in OVX mice, as compared to all other experimental groups, at 7 and 14 days after surgery. Astrocyte activation was higher in OVX mice with respect the other experimental groups, at all time points. Microglial activation in the SNc was detected at earlier time points in male, female and OVX+E, while in OVX mice was detected at all time-points. Microglia polarization toward the M2, but not the M1, phenotype was detected in female and OVX+E mice, while the M1 phenotype was observed only in male and OVX mice. Our results support the protective effects of estrogens against nigrostriatal degeneration, suggesting that such effects may be mediated by an interaction with microglia, which tend to polarize preferentially toward an M2, cytoprotective phenotype in the presence of intense estrogenic stimulation

Proton and molecular permeation through the basal plane of monolayer graphene oxide

Two-dimensional (2D) materials offer a prospect of membranes that combine negligible gas permeability with high proton conductivity and could outperform the existing proton exchange membranes used in various applications including fuel cells. Graphene oxide (GO), a well-known 2D material, facilitates rapid proton transport along its basal plane but proton conductivity across it remains unknown. It is also often presumed that individual GO monolayers contain a large density of nanoscale pinholes that lead to considerable gas leakage across the GO basal plane. Here we show that relatively large, micrometer-scale areas of monolayer GO are impermeable to gases, including helium, while exhibiting proton conductivity through the basal plane which is nearly two orders of magnitude higher than that of graphene. These findings provide insights into the key properties of GO and demonstrate that chemical functionalization of 2D crystals can be utilized to enhance their proton transparency without compromising gas impermeability

The ARROWS project: Adapting and developing robotics technologies for underwater archaeology

ARchaeological RObot systems for the World's Seas (ARROWS) EU Project proposes to adapt and develop low-cost Autonomous Underwater Vehicle (AUV) technologies to significantly reduce the cost of archaeological operations, covering the full extent of archaeological campaign. ARROWS methodology is to identify the archaeologists requirements in all phases of the campaign and to propose related technological solutions. Starting from the necessities identified by archaeological project partners in collaboration with the Archaeology Advisory Group, a board composed of European archaeologists from outside ARROWS, the aim is the development of a heterogeneous team of cooperating AUVs capable of comply with a complete archaeological autonomous mission. Three new different AUVs have been designed in the framework of the project according to the archaeologists' indications: MARTA, characterized by a strong hardware modularity for ease of payload and propulsion systems configuration change; U-C AT, a turtle inspired bio-mimetic robot devoted to shipwreck penetration and A-Size AUV, a vehicle of small dimensions and weight easily deployable even by a single person. These three vehicles will cooperate within the project with AUVs already owned by ARROWS partners exploiting a distributed high-level control software based on the World Model Service (WMS), a storage system for the environment knowledge, updated in real-time through online payload data process, in the form of an ontology. The project includes also the development of a cleaning tool for well-known artifacts maintenance operations. The paper presents the current stage of the project that will lead to overall system final demonstrations, during Summer 2015, in two different scenarios, Sicily (Italy) and Baltic Sea (Estonia

Proton transport through nanoscale corrugations in two-dimensional crystals

Defect-free graphene is impermeable to all atoms1,2,3,4,5 and ions6,7 under ambient conditions. Experiments that can resolve gas flows of a few atoms per hour through micrometre-sized membranes found that monocrystalline graphene is completely impermeable to helium, the smallest atom2,5. Such membranes were also shown to be impermeable to all ions, including the smallest one, lithium6,7. By contrast, graphene was reported to be highly permeable to protons, nuclei of hydrogen atoms8,9. There is no consensus, however, either on the mechanism behind the unexpectedly high proton permeability10,11,12,13,14 or even on whether it requires defects in graphene’s crystal lattice6,8,15,16,17. Here, using high-resolution scanning electrochemical cell microscopy, we show that, although proton permeation through mechanically exfoliated monolayers of graphene and hexagonal boron nitride cannot be attributed to any structural defects, nanoscale non-flatness of two-dimensional membranes greatly facilitates proton transport. The spatial distribution of proton currents visualized by scanning electrochemical cell microscopy reveals marked inhomogeneities that are strongly correlated with nanoscale wrinkles and other features where strain is accumulated. Our results highlight nanoscale morphology as an important parameter enabling proton transport through two-dimensional crystals, mostly considered and modelled as flat, and indicate that strain and curvature can be used as additional degrees of freedom to control the proton permeability of two-dimensional materials

Scanning electrochemical cell microscopy : high-resolution structure−property studies of mono- and polycrystalline electrode materials

Scanning electrochemical cell microscopy (SECCM) is a nanopipette-based scanning electrochemical probe microscopy technique that utilises a mobile droplet cell to measure and visualise electrode activity with high spatiotemporal resolution. This article spotlights the use of SECCM for studying the electrochemistry of crystalline electrode materials, ranging from well-defined monocrystals (e.g., transition metal dichalcogenides: MoS2, WS2 and WSe2) to structurally/compositionally heterogeneous polycrystals (e.g., polycrystalline Pt, Au, Pd, Cu, Zn, low carbon steel, boron-doped diamond) and covering the diverse areas of (photo)electrocatalysis, corrosion science, surface science and electroanalysis. In particular, it is emphasised how nanoscale-resolved information from SECCM is readily related to electrode structure and properties, collected at a commensurate scale with complementary, co-located microscopy/spectroscopy techniques, to allow structure−property relationships to be assigned directly and unambiguously

Cell and tissue patterning starfish arm regeneration: a microscopic overview

Purpose: to provide a comprehensive overview of cell and tissue patterning of starfish regenerative processes Methods: Two ecologically different starfish species (Marthasterias glacialis and Echinaster sepositus) were subjected to traumatic arm tip amputation and left to regenerate for prefixed periods (up to 16 weeks). In E. sepositus experiments on isolated arm explants (double-amputated) were also performed. Regenerating samples were analysed by light- and electron microscopy analyses. Results: In both species, in both species, arm tip regeneration follows three main phases: a) a repair phase resembling the vertebrate\u2019s one and characterized by haemostasis, tissue remodelling, rapid re-epithelialization and \u201coedema\u201d (granulation-like tissue) formation; b) an early regenerative phase, where no localized blastema is observed and extensive recruitment/recycling of myocytes occur in parallel to first differentiation events and regrowth of the main \u201cpilot\u201d structures,, i.e. radial nerve cord and coelomic canals; c) an advanced regenerative phase characterized by complete differentiation, morphogenesis and growth of the regenerate following a distalization-intercalation model. The arm explant model, although both amputated ends undergo partial tissue regeneration, emphasizes a polarized regenerative growth in proximal-distal direction. Conclusions: Our results confirm that starfish regeneration relies on a remodelling and recycling of the existing tissues (mainly myocytes) without any blastemal formation. This morphallactic regenerative process follows a distalization-intercalation mechanism according to proximal-distal growth patterning, as observed in other regenerative animal models (e.g. planarians, amphibians). Overall this overview underlines also that starfish can be valid regeneration models to be compared to vertebrates

Arm-tip regeneration in the spiny starfish Marthasterias glacialis: an integrated approach

Starfish (Echinodermata, Asteroidea) possess striking regenerative capabilities being able to replace lost body structures after both autotomy and traumatic amputation. We selected the Mediterranean-Atlantic starfish Marthasterias glacialis (Linnaeus, 1758) as experimental model to study the arm-tip regeneration. The aims of this research are to describe in detail the complex cell and tissue patterning during M. glacialis regenerative process and to provide a complementary morphological perspective to previous and on-going proteomic studies [1]. Specimens of M. glacialis were collected in the west coast of Portugal (Estoril, Cascais) and subjected to traumatic arm-tip amputation. Regeneration tests were performed at different time-points: 48 hours, 13 days, 3, 6 and 10 weeks post amputation (p.a.). Regenerating samples were processed for both light and electron (TEM and SEM) microscopy analysis. As for other Asteroids, in M. glacialis the process can be divided in three main phases: a) repair phase (until 48h p.a.) during which wound closure and healing phenomena take place; b) early regenerative phase (13d\u20133w p.a.) where dedifferentiation, rearrangement and first signs of differentiation occur and c) advanced regenerative phase (up 3w p.a.) characterized by complete differentiation,morphogenesis and re-growth of the lost body structures with the formation of a miniaturized arm. Our results confirm that M. glacialis arm regeneration is mainly based on morphallactic mechanisms including 1) rearrangement and dedifferentiation of the stump tissues possibly used as source of cells (mainly from coelomic epithelium) for the subsequent regrowth of the new arm-tip, 2) lack of a well-defined undifferentiated blastema, although the presence of a widespread \u201cblastemal connective tissue\u201d is detectable, underlining the need to review classical epimorphosis/morphallaxis definitions. M. glacialis regenerative process can be well described by the \u201cdistalization-intercalation\u201d regenerative model re-proposed for starfish by [2]: indeed, the first body structures reformed are the most distal ones and the new tissues subsequently differentiate by intercalation between these latter and the stump, following a proximal-distal gradient. Current proteomic studies on coelomic epithelium/cells will help to clarify the role of this tissue during regeneration. [1] Franco C.F. et al., 2011. Proteomics (2011), 11: pp 3587-3592. [2] Ben Khadra et al., 2015. WRR 23(4), pp 623-634

The coelomic epithelium and coelomocytes of the starfish Marthasterias glacialis (Linnaeus, 1758) in non-regenerating ARM-TIP: microscopic anatomy and proteomics characterization

In echinoderms the coelomic epithelium (CE) is hypothesized to be the source of circulating coelomocytes, echinoderms' immune cells, and to play a key role during arm regeneration as source of stem cells. In this context, we decided to characterize the starfish CE and free wandering coelomocytes (CO) in non-regenerating conditions by means of a multidisciplinary approach combining microscopy and proteomics analyses. This was done in an attempt to address the above mentioned issues and provide a fundamental basis for further regeneration studies. For this purpose, we used Marthasterias glacialis as model system. For microscopy analyses, CE and circulating CO were collected and processed for standard protocols of light and transmission electron microscopy (TEM). For proteomics analysis, the CE was removed from amputated arms and processed for the identification of soluble proteins by Liquid Chromatography Tandem-Mass Spectrometry (LC-MS/MS) analysis. Microscopy results confirmed that M. glacialis CE presents the same complex multi-layered structure described for other asteroids. However, we observed the presence of a never described layer of flagellated cells, filled by swollen RER cisternae. TEM images indicated that the peritoneocytes are actively involved in apocrine-like secretion, especially in the distal most arm-tip. Among the CO, we identified two main subpopulations: a thrombocyte-like cytotype, characterized by numerous electron-lucent vesicles and several long filopodia, and a macrophage-like cytotype (immunocytes), characterized by a less electron-dense cytoplasm, phagosomes and short cytoplasmic processes. No presumptive stem cells were found among the circulating CO. Proteomics results indicated that the CE contains proteins involved in the rearrangement of the cytoskeleton, related to phagocytosis and endocytosis, proteins involved in the immunity response, and in apocrine secretion. Overall, our findings suggested that M. glacialis CE and CO are involved in several physiological functions: active secretion of protein material, some of this possibly needed for the distal arm growth; immune-related functions, such as pathogen or endogenous cell removal; haemostatic function. Shared ultrastructural features between CE and CO suggested that at least one of the CO subpopulations might derive from the CE. Further integrated studies on normal and regenerating arms are necessary to deeply understand the role of CE and CO in starfish physiology