In humans, disruption of nonsense-mediated decay (NMD) has been associated with neurodevelopmental disorders (NDDs) such as autism spectrum disorder and intellectual disability. However, the ...mechanism by which deficient NMD leads to neurodevelopmental dysfunction remains unknown, preventing development of targeted therapies. Here we identified novel protein-coding UPF2 (UP-Frameshift 2) variants in humans with NDD, including speech and language deficits. In parallel, we found that mice lacking Upf2 in the forebrain (Upf2 fb-KO mice) show impaired NMD, memory deficits, abnormal long-term potentiation (LTP), and social and communication deficits. Surprisingly, Upf2 fb-KO mice exhibit elevated expression of immune genes and brain inflammation. More importantly, treatment with two FDA-approved anti-inflammatory drugs reduced brain inflammation, restored LTP and long-term memory, and reversed social and communication deficits. Collectively, our findings indicate that impaired UPF2-dependent NMD leads to neurodevelopmental dysfunction and suggest that anti-inflammatory agents may prove effective for treatment of disorders with impaired NMD.
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•Humans carrying novel variants in UPF2 exhibit speech and language deficits•Upf2-deficient mice and flies have impaired NMD and exhibit behavioral deficits•Inhibition of Upf2-dependent NMD triggers immune activation in mice•Reduction of brain inflammation reverses synaptic and behavioral deficits
Johnson et al. discovered that genetic ablation of Upf2-mediated NMD triggers an aberrant immune response and leads to memory, synaptic plasticity, social, and vocal communication deficits. These behavioral and neurophysiological abnormalities were reversed by FDA-approved agents that dampen brain inflammation.
Autoreactive memory T lymphocytes are implicated in the pathogenesis of autoimmune diseases. Here we demonstrate that disease-associated autoreactive T cells from patients with type-1 diabetes ...mellitus or rheumatoid arthritis (RA) are mainly CD4⁺CCR7⁻CD45RA⁻ effector memory T cells ($T_{EM}$cells) with elevated Kv1.3 potassium channel expression. In contrast, T cells with other antigen specificities from these patients, or autoreactive T cells from healthy individuals and disease controls, express low levels of Kv1.3 and are predominantly naíve or central-memory ($T_{CM}$) cells. In$T_{EM}$cells, Kv1.3 traffics to the immunological synapse during antigen presentation where it colocalizes with Kvβ2, SAP97, ZIP,$p56^{Ick}$, and CD4. Although Kv1.3 inhibitors ShK(L5)-amide (SL5) and PAP1 do not prevent immunological synapse formation, they suppress Ca²⁺-signaling, cytokine production, and proliferation of autoantigen-specific$T_{EM}$cells at pharmacologically relevant concentrations while sparing other classes of T cells. Kv1.3 inhibitors ameliorate pristane-induced arthritis in rats and reduce the incidence of experimental autoimmune diabetes in diabetes-prone (DP-BB/W) rats. Repeated dosing with Kv1.3 inhibitors in rats has not revealed systemic toxicity. Further development of Kv1.3 blockers for autoimmune disease therapy is warranted.
Engineered microbes for the delivery of biologics are a promising avenue for the treatment of various conditions such as chronic inflammatory disorders and metabolic disease. In this study, we ...developed a genetically engineered probiotic delivery system that delivers a peptide to the intestinal tract with high efficacy. We constructed an inducible system in the probiotic
to secrete the Kv1.3 potassium blocker ShK-235 (LrS235). We show that LrS235 culture supernatants block Kv1.3 currents and preferentially inhibit human T effector memory (T
) lymphocyte proliferation in vitro. A single oral gavage of healthy rats with LrS235 resulted in sufficient functional ShK-235 in the circulation to reduce inflammation in a delayed-type hypersensitivity model of atopic dermatitis mediated by T
cells. Furthermore, the daily oral gavage of LrS235 dramatically reduced clinical signs of disease and joint inflammation in rats with a model of rheumatoid arthritis without eliciting immunogenicity against ShK-235. This work demonstrates the efficacy of using the probiotic
as a novel oral delivery platform for the peptide ShK-235 and provides an efficacious strategy to deliver other biologics with great translational potential.
Tools for exploring and communicating the impact of uncertainty on spatial prediction are urgently needed, particularly when projecting species distributions to future conditions.
We provide a tool ...for simulating uncertainty, focusing on uncertainty due to data quality. We illustrate the use of the tool using a Tasmanian endemic species as a case study. Our simulations provide probabilistic, spatially explicit illustrations of the impact of uncertainty on model projections. We also illustrate differences in model projections using six different global climate models and two contrasting emissions scenarios.
Our case study results illustrate how different sources of uncertainty have different impacts on model output and how the geographic distribution of uncertainty can vary.
Synthesis and applications: We provide a conceptual framework for understanding sources of uncertainty based on a review of potential sources of uncertainty in species distribution modelling; a tool for simulating uncertainty in species distribution models; and protocols for dealing with uncertainty due to climate models and emissions scenarios. Our tool provides a step forward in understanding and communicating the impacts of uncertainty on species distribution models under future climates which will be particularly helpful for informing discussions between researchers, policy makers, and conservation practitioners.
We review potential sources of uncertainty in species distribution modelling under future climates and provide a tool for simulating uncertainty in a spatially explicit way. We also outline protocols for dealing with uncertainty due to climate models and emissions scenarios.
Ureaplasmas are some of the smallest and simplest free-living organisms known. Little is understood regarding the effects of the complement system upon clearance of these pathogens, but when the ...immune system fails to control Ureaplasma colonization disease, such as chronic lung disease of prematurity (CLD), can occur. Treatment of such Ureaplasma infections, especially in neonates, is limited by pathogen and host factors. Treatment can be further compromised by antibiotic resistance. Firstly this thesis examines an in vitro system for determining the bactericidal capacity of a selection of human sera against four representative serovars of Ureaplasma parvum. Results showed that the classical activation pathway was essential for the killing of all U. parvum serovars, with little effect being attributed to the alternative or lectin pathways. Additionally serovar 3 was shown to be the most serum sensitive isolate. Secondly the association between presence of Ureaplasma and 16S rRNA with development of CLD was examined in a prospective cohort of 192 neonates. Data suggested that presence of Ureaplasma as well as 16S rRNA was significantly associated with development of CLD as well as increased levels of inflammatory mediators IL-6 and IL-8. Finally a retrospective cohort of 61 Ureaplasma isolates was examined for resistance to various antibiotics. High level macrolide resistance in isolate UHWO10 resulted from a two amino acid deletion within the L4 ribosomal protein (R66Q67). Tetracycline resistance in isolate HPA23 resulted from the presence of the tetM gene while a ciprofloxacin resistance in isolate HPA18 resulted from a D82N substitution within the ParC protein. No differences were found in the GyrA, GyrB or ParE proteins. Comparison of type II topoisomerase genes from all Ureaplasma serovars revealed that mutations previously associated with resistance where wrongly identified and were a result of species or serovar specific polymorphisms.
Ureaplasmas are some of the smallest and simplest free-living organisms known. Little is understood regarding the effects of the complement system upon clearance of these pathogens, but when the ...immune system fails to control Ureaplasma colonization disease, such as chronic lung disease of prematurity (CLD), can occur. Treatment of such Ureaplasma infections, especially in neonates, is limited by pathogen and host factors. Treatment can be further compromised by antibiotic resistance. Firstly this thesis examines an in vitro system for determining the bactericidal capacity of a selection of human sera against four representative serovars of Ureaplasma parvum. Results showed that the classical activation pathway was essential for the killing of all U. parvum serovars, with little effect being attributed to the alternative or lectin pathways. Additionally serovar 3 was shown to be the most serum sensitive isolate. Secondly the association between presence of Ureaplasma and 16S rRNA with development of CLD was examined in a prospective cohort of 192 neonates. Data suggested that presence of Ureaplasma as well as 16S rRNA was significantly associated with development of CLD as well as increased levels of inflammatory mediators IL-6 and IL-8. Finally a retrospective cohort of 61 Ureaplasma isolates was examined for resistance to various antibiotics. High level macrolide resistance in isolate UHWO10 resulted from a two amino acid deletion within the L4 ribosomal protein (R66Q67). Tetracycline resistance in isolate HPA23 resulted from the presence of the tetM gene while a ciprofloxacin resistance in isolate HPA18 resulted from a D82N substitution within the ParC protein. No differences were found in the GyrA, GyrB or ParE proteins. Comparison of type II topoisomerase genes from all Ureaplasma serovars revealed that mutations previously associated with resistance where wrongly identified and were a result of species or serovar specific polymorphisms.
BACKGROUND: Ca2+ influx through CaV1.1 is not required for skeletal muscle excitation-contraction coupling, but whether Ca2+ permeation through CaV1.1 during sustained muscle activity plays a ...functional role in mammalian skeletal muscle has not been assessed. METHODS: We generated a mouse with a Ca2+ binding and/or permeation defect in the voltage-dependent Ca2+ channel, CaV1.1, and used Ca2+ imaging, western blotting, immunohistochemistry, proximity ligation assays, SUnSET analysis of protein synthesis, and Ca2+ imaging techniques to define pathways modulated by Ca2+ binding and/or permeation of CaV1.1. We also assessed fiber type distributions, cross-sectional area, and force frequency and fatigue in isolated muscles. RESULTS: Using mice with a pore mutation in CaV1.1 required for Ca2+ binding and/or permeation (E1014K, EK), we demonstrate that CaV1.1 opening is coupled to CaMKII activation and refilling of sarcoplasmic reticulum Ca2+ stores during sustained activity. Decreases in these Ca2+-dependent enzyme activities alter downstream signaling pathways (Ras/Erk/mTORC1) that lead to decreased muscle protein synthesis. The physiological consequences of the permeation and/or Ca2+ binding defect in CaV1.1 are increased fatigue, decreased fiber size, and increased Type IIb fibers. CONCLUSIONS: While not essential for excitation-contraction coupling, Ca2+ binding and/or permeation via the CaV1.1 pore plays an important modulatory role in muscle performance.
Drought is a complex phenomenon manifested through interactions between biophysical and social factors. At the Wind River Indian Reservation (WRIR) in west-central Wyoming, water shortages have ...become increasingly common since the turn of the 21st century. Here we discuss the 2015 water year as an exemplar year, which was characterized by wetter-than-normal conditions across the reservation and, according to the U.S. Drought Monitor, remained drought-free throughout the year. Yet parts of the reservation experienced harmful water shortages, or “micro-drought” conditions, during the growing season in 2015. In this assessment of the 2015 water year at the WRIR we: (1) describe the hydroclimatic and social processes under way that contributed to the 2015 water year micro-drought in the Little Wind Basin; (2) compare water availability conditions within and between other basins at the WRIR to illustrate how micro-droughts can result from social and environmental features unique to local systems; and (3) describe how a collaborative project is supporting drought preparedness at the WRIR. We combine a social science assessment with an analysis of the hydroclimate to deconstruct how shortages manifest at the WRIR. We provide insights from this study to help guide drought assessments at local scales.
We describe a cysteine-rich, membrane-penetrating, joint-targeting, and remarkably stable peptide, EgK5, that modulates voltage-gated KV1.3 potassium channels in T lymphocytes by a distinctive ...mechanism. EgK5 enters plasma membranes and binds to KV1.3, causing current run-down by a phosphatidylinositol 4,5-bisphosphate-dependent mechanism. EgK5 exhibits selectivity for KV1.3 over other channels, receptors, transporters, and enzymes. EgK5 suppresses antigen-triggered proliferation of effector memory T cells, a subset enriched among pathogenic autoreactive T cells in autoimmune disease. PET-CT imaging with 18F-labeled EgK5 shows accumulation of the peptide in large and small joints of rodents. In keeping with its arthrotropism, EgK5 treats disease in a rat model of rheumatoid arthritis. It was also effective in treating disease in a rat model of atopic dermatitis. No signs of toxicity are observed at 10–100 times the in vivo dose. EgK5 shows promise for clinical development as a therapeutic for autoimmune diseases.
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