The effect of tissue preparation and donor age on striatal graft morphology in the mouse

Huntington's disease (HD) is a progressive neurodegenerative disease in which striatal medium spiny neurons (MSNs) are lost. Neuronal replacement therapies aim to replace MSNs through striatal transplantation of donor MSN progenitors, which successfully improve HD-like deficits in rat HD models and have provided functional improvement in patients. Transplants in mouse models of HD are more variable and have lower cell survival than equivalent rat grafts, yet mice constitute the majority of transgenic HD models. Improving the quality and consistency of mouse transplants would open up access to this wider range of rodent models and facilitate research to increase understanding of graft mechanisms, which is essential to progress transplantation as a therapy for HD. Here we determined how donor age, cell preparation, and donor/host strain choice influenced the quality of primary embryonic grafts in quinolinic acid lesion mouse models of HD. Both a within-strain (W-S) and a between-strain (B-S) donor/host paradigm were used to compare transplants of donor tissues derived from mice at embryonic day E12 and E14 prepared either as dissociated suspensions or as minimally manipulated tissue pieces (TP). Good graft survival was observed, although graft volume and cellular composition were highly variable. The effect of cell preparation on grafts differed significantly depending on donor age, with E14 cell suspensions yielding larger grafts compared to TP. Conversely, TP were more effective when derived from E12 donor tissue. A W-S model produced larger grafts with greater MSN content, and while high levels of activated microglia were observed across all groups, a greater number was found in B-S transplants. In summary, we show that the effect of tissue preparation on graft morphology is contingent on the age of donor tissue used. The presence of microglial activation in all groups highlights the host immune response as an important consideration in mouse transplantation

Imaging Proteins Sensitive to Direct Fusions Using Transient Peptide–Peptide Interactions

Fluorescence microscopy enables specific visualization of proteins in living cells and has played an important role in our understanding of the protein subcellular location and function. Some proteins, however, show altered localization or function when labeled using direct fusions to fluorescent proteins, making themdifficult to study in live cells. Additionally, the resolution of fluorescence microscopy is limited to ∼200 nm, which is 2 orders of magnitude larger than the size of most proteins. To circumvent these challenges, we previously developed LIVE-PAINT, a live-cell superresolution approach that takes advantage of short interacting peptides to transiently bind a fluorescent protein to the protein-ofinterest. Here, we successfully use LIVE-PAINT to image yeastmembrane proteins that do not tolerate the direct fusion of a fluorescent protein by using peptide tags as short as 5-residues. We also demonstrate that it is possible to resolve multiple proteins at the nanoscale concurrently using orthogonal peptide interaction pairs.KEYWORDS: membrane protein, protein−protein interaction, super-resolution microscopy, live-cell imaging, LIVE-PAINT, yeas

Exercise attenuates neuropathology and has greater benefit on cognitive than motor deficits in the R6/1 Huntington's disease mouse model

Huntington's disease (HD) is a neurodegenerative disease caused by a mutation within the huntingtin gene that induces degeneration within the striatal nuclei, progressing to widespread brain atrophy and death. The neurodegeneration produces symptoms that reflect a corticostriatal disconnection syndrome involving motor, cognitive and psychiatric disturbances. Environmental enrichment has been demonstrated to be beneficial to patients with neurological disorders, with exercise being central to this effect. Rodent studies have confirmed exercise-induced neurogenesis and increased growth factor levels in the brain and improved behavioural function. The present study sought to determine whether an extended regime of exercise could retard disease progression in the R6/1 mouse model of HD. The study was designed specifically with a translational focus, selecting behavioural assessments with high clinical predictive validity. We found that exercise improved gait function in both control and HD mice and selectively improved performance in the R6/1 mice on a motor coordination aspect of the balance beam task. Exercise also retarded the progression of cognitive dysfunction on water T-maze procedural and reversal learning probes presented serially to probe cognitive flexibility. In addition, exercise reduced striatal neuron loss in the R6/1 mice but increased striatal neuronal intra-nuclear inclusion size and number relative to non-exercised R6/1 mice which demonstrated increased numbers of extra-neuronal inclusions, suggesting that the functional effects were striatally mediated. These results confirm and extend those from previous studies that demonstrate that HD may be amenable to exercise-mediated therapeutics, but suggest that the impact of such interventions may be primarily cognitive

Asymmetric distribution of pl10 and bruno2, new members of a conserved core of early germline determinants in cephalochordates

Molecular fingerprinting of conserved germline and somatic "stemness" markers in different taxa have been key in defining the mechanism of germline specification ("preformation" or "epigenesis"), as well as expression domains of somatic progenitors. The distribution of molecular markers for primordial germ cells (PGCs), including vasa, nanos, and piwil1, as well as Vasa antibody staining, support a determinative mechanism of germline specification in the cephalochordate Branchiostoma lanceolatum, similarly to other amphioxus species. pl10 and bruno2, but not bruno4/6, are also expressed in a pattern consistent with these other germline genes, adding to our repertoire of PGC markers in lancelets. Expression of nanos, vasa, and the remaining markers (musashi, pufA, pufB, pumilio, and piwil2) may define populations of putative somatic progenitors in the tailbud, the amphioxus posterior growth zone, or zones of proliferative activity. Finally, we also identify a novel expression domain for musashi, a classic neural stem cell marker, during notochord development in amphioxus. These results are discussed in the context of germline determination in other taxa, stem cell regulation, and regenerative capacity in adult amphioxus

Detection of slow‐moving landslides through automated monitoring of surface deformation using Sentinel‐2 satellite imagery

Landslides are one of the most damaging natural hazards and have killed tens of thousands of people around the world over the past decade. Slow‐moving landslides, with surface velocities on the order of 10−2–102 m a−1, can damage buildings and infrastructure and be precursors to catastrophic collapses. However, due to their slow rates of deformation and at times subtle geomorphic signatures, they are often overlooked in local and large‐scale hazard inventories. Here, we present a remote‐sensing workflow to automatically map slow‐moving landslides using feature tracking of freely and globally available optical satellite imagery. We evaluate this proof‐of‐concept workflow through three case studies from different environments: the extensively instrumented Slumgullion landslide in the United States, an unstable lateral moraine in Chilean Patagonia and a high‐relief landscape in central Nepal. This workflow is able to delineate known landslides and identify previously unknown areas of hillslope deformation, which we consider as candidate slow‐moving landslides. Improved mapping of the spatial distribution, character and surface displacement rates of slow‐moving landslides will improve our understanding of their role in the multi‐hazard chain and their sensitivity to climatic changes and can direct future detailed localised investigations into their dynamics

Limited Awareness and Low Immediate Uptake of Pre-Exposure Prophylaxis among Men Who Have Sex with Men Using an Internet Social Networking Site

Background: In 2010, the iPrEx trial demonstrated that oral antiretroviral pre-exposure prophylaxis (PrEP) reduced the risk of HIV acquisition among high-risk men who have sex with men (MSM). The impact of iPrEx on PrEP knowledge and actual use among at-risk MSM is unknown. Online surveys were conducted to assess PrEP awareness, interest and experience among at-risk MSM before and after iPrEx, and to determine demographic and behavioral factors associated with these measures. Methods and Findings: Cross-sectional, national, internet-based surveys were administered to U.S. based members of the most popular American MSM social networking site 2 months before (n = 398) and 1 month after (n = 4 558) publication of iPrEx results. Comparisons were made between these samples with regards to PrEP knowledge, interest, and experience. Data were collected on demographics, sexual risk, and experience with post-exposure prophylaxis (PEP). Regression analyses were performed to identify factors associated with PrEP awareness, interest, and experience post-iPrEx. Most participants were white, educated, and indicated high-risk sexual behaviors. Awareness of PrEP was limited pre- and post-iPrEx (13% vs. 19%), whereas interest levels after being provided with a description of PrEP remained high (76% vs. 79%). PrEP use remained uncommon (0.7% vs. 0.9%). PrEP use was associated with PEP awareness (OR 7.46; CI 1.52–36.6) and PEP experience (OR 34.2; CI 13.3–88.4). PrEP interest was associated with older age (OR 1.01; CI 1.00–1.02), unprotected anal intercourse with ≥1 male partner in the prior 3 months (OR 1.40; CI 1.10–1.77), and perceiving oneself at increased risk for HIV acquisition (OR 1.20; CI 1.13–1.27). Conclusions: Among MSM engaged in online networking, awareness of PrEP was limited 1 month after the iPrEx data were released. Utilization was low, although some MSM who reported high-risk behaviors were interested in using PrEP. Studies are needed to understand barriers to PrEP utilization by at-risk MSM

Role of CD14+ monocyte-derived oxidised mitochondrial DNA in the inflammatory interferon type 1 signature in juvenile dermatomyositis

OBJECTIVES: To define the host mechanisms contributing to the pathological interferon (IFN) type 1 signature in Juvenile dermatomyositis (JDM). METHODS: RNA-sequencing was performed on CD4+, CD8+, CD14+ and CD19+ cells sorted from pretreatment and on-treatment JDM (pretreatment n=10, on-treatment n=11) and age/sex-matched child healthy-control (CHC n=4) peripheral blood mononuclear cell (PBMC). Mitochondrial morphology and superoxide were assessed by fluorescence microscopy, cellular metabolism by 13C glucose uptake assays, and oxidised mitochondrial DNA (oxmtDNA) content by dot-blot. Healthy-control PBMC and JDM pretreatment PBMC were cultured with IFN-α, oxmtDNA, cGAS-inhibitor, TLR-9 antagonist and/or n-acetyl cysteine (NAC). IFN-stimulated gene (ISGs) expression was measured by qPCR. Total numbers of patient and controls for functional experiments, JDM n=82, total CHC n=35. RESULTS: Dysregulated mitochondrial-associated gene expression correlated with increased ISG expression in JDM CD14+ monocytes. Altered mitochondrial-associated gene expression was paralleled by altered mitochondrial biology, including 'megamitochondria', cellular metabolism and a decrease in gene expression of superoxide dismutase (SOD)1. This was associated with enhanced production of oxidised mitochondrial (oxmt)DNA. OxmtDNA induced ISG expression in healthy PBMC, which was blocked by targeting oxidative stress and intracellular nucleic acid sensing pathways. Complementary experiments showed that, under in vitro experimental conditions, targeting these pathways via the antioxidant drug NAC, TLR9 antagonist and to a lesser extent cGAS-inhibitor, suppressed ISG expression in pretreatment JDM PBMC. CONCLUSIONS: These results describe a novel pathway where altered mitochondrial biology in JDM CD14+ monocytes lead to oxmtDNA production and stimulates ISG expression. Targeting this pathway has therapeutical potential in JDM and other IFN type 1-driven autoimmune diseases

Exploring the lived experience of gay men with prostate cancer: A phenomenological study

Purpose: Gay men with prostate cancer are an ‘invisible species’ in the research literature despite concerns that the impact of treatment may be more profound and in some ways unique compared to heterosexual men. The aim of this research is to explore the lived experience of gay men with prostate cancer. Method: In-depth interviews were recorded and transcribed verbatim from a purposive sample of eight gay men treated for prostate cancer in Ireland. A qualitative methodological approach employing Giorgi's descriptive phenomenological method was used to collect and analyse data. Findings: Three key aspects emerged representing the essence of the participants lived experience; The experience of diagnosis, treatment decision making, and the impact of treatment, with sub-themes of shock of diagnosis, the generalist nature of information, sexual side effects and incontinence, and masculinity and gay identity. Secondly, the experience of the healthcare service with sub-themes of sexual orientation disclosure and communication with the healthcare team; and thirdly, sources of support and means of coping which included significant others, family & friends, cancer support groups, and gay resources and support services. Conclusion: Gay men with prostate cancer have unmet information and supportive care needs throughout their prostate cancer journey, especially related to the impact of sexual dysfunction and associated rehabilitation, negatively impacting their quality of life. Issues associated with heteronormativity, minority stress, and stigma may influence how gay men interact with the health service, or how they perceive the delivery of care. Healthcare education providers should update prostate cancer education programmes accordingly

Boolean Dynamics with Random Couplings

This paper reviews a class of generic dissipative dynamical systems called N-K models. In these models, the dynamics of N elements, defined as Boolean variables, develop step by step, clocked by a discrete time variable. Each of the N Boolean elements at a given time is given a value which depends upon K elements in the previous time step. We review the work of many authors on the behavior of the models, looking particularly at the structure and lengths of their cycles, the sizes of their basins of attraction, and the flow of information through the systems. In the limit of infinite N, there is a phase transition between a chaotic and an ordered phase, with a critical phase in between. We argue that the behavior of this system depends significantly on the topology of the network connections. If the elements are placed upon a lattice with dimension d, the system shows correlations related to the standard percolation or directed percolation phase transition on such a lattice. On the other hand, a very different behavior is seen in the Kauffman net in which all spins are equally likely to be coupled to a given spin. In this situation, coupling loops are mostly suppressed, and the behavior of the system is much more like that of a mean field theory. We also describe possible applications of the models to, for example, genetic networks, cell differentiation, evolution, democracy in social systems and neural networks.Comment: 69 pages, 16 figures, Submitted to Springer Applied Mathematical Sciences Serie