Preclinical characterization of antagomiR-218 as a potential treatment for myotonic dystrophy

Myotonic dystrophy type 1 (DM1) is a rare neuromuscular disease caused by expansion of unstable CTG repeats in a non-coding region of the DMPK gene. CUG expansions in mutant DMPK transcripts sequester MBNL1 proteins in ribonuclear foci. Depletion of this protein is a primary contributor to disease symptoms such as muscle weakness and atrophy and myotonia, yet upregulation of endogenous MBNL1 levels may compensate for this sequestration. Having previously demonstrated that antisense oligonucleotides against miR-218 boost MBNL1 expression and rescue phenotypes in disease models, here we provide preclinical characterization of an antagomiR-218 molecule using the HSALR mouse model and patient-derived myotubes. In HSALR, antagomiR-218 reached 40-60 pM 2weeks after injection, rescued molecular and functional phenotypes in a dose- and time-dependent manner, and showed a good toxicity profile after a single subcutaneous administration. In muscle tissue, antagomiR rescued the normal subcellular distribution of Mbnl1 and did not alter the proportion of myonuclei containing CUG foci. In patient-derived cells, antagomiR-218 improved defective fusion and differentiation and rescued up to 34% of the gene expression alterations found in the transcriptome of patient cells. Importantly, miR-218 was found to be upregulated in DM1 muscle biopsies, pinpointing this microRNA (miRNA) as a relevant therapeutic target.This work was funded by research grants from Instituto de Salud Carlos III, including funds from FEDER, to M.P.-A. and B.L. (PI17/00352) and HR17-00268 (TATAMI project) from the “la Caixa” Banking Foundation to R.A. I.G.-M. was funded by the Precipita Project titled “Desarrollo de una terapia innovadora contra la distrofia miotónica,” E.C.-H. and J.M.F.-C. were supported by the post-doctoral fellowships APOSTD/2019/142 and APOSTD/2017/088 from the Fondo Social Europeo for science and investigation, while J.E.-E. was the recipient of a Santiago Grisolia fellowship (Grisolip2018/098) from the Generalidad Valenciana. Part of the equipment employed in this work has been funded by Generalitat Valenciana and co-financed with ERDF funds (OP ERDF of Comunitat Valenciana 2014-2020). Antibody MB1a (4A8) was provided by MDA Monoclonal Antibody Resource

Decadal changes in fire frequencies shift tree communities and functional traits

Global change has resulted in chronic shifts in fire regimes. Variability in the sensitivity of tree communities to multi-decadal changes in fire regimes is critical to anticipating shifts in ecosystem structure and function, yet remains poorly understood. Here, we address the overall effects of fire on tree communities and the factors controlling their sensitivity in 29 sites that experienced multi-decadal alterations in fire frequencies in savanna and forest ecosystems across tropical and temperate regions. Fire had a strong overall effect on tree communities, with an average fire frequency (one fire every three years) reducing stem density by 48% and basal area by 53% after 50 years, relative to unburned plots. The largest changes occurred in savanna ecosystems and in sites with strong wet seasons or strong dry seasons, pointing to fire characteristics and species composition as important. Analyses of functional traits highlighted the impact of fire-driven changes in soil nutrients because frequent burning favoured trees with low biomass nitrogen and phosphorus content, and with more efficient nitrogen acquisition through ectomycorrhizal symbioses. Taken together, the response of trees to altered fire frequencies depends both on climatic and vegetation determinants of fire behaviour and tree growth, and the coupling between fire-driven nutrient losses and plant traits

Inverting the model of genomics data sharing with the NHGRI Genomic Data Science Analysis, Visualization, and Informatics Lab-space

The NHGRI Genomic Data Science Analysis, Visualization, and Informatics Lab-space (AnVIL; https://anvilproject.org) was developed to address a widespread community need for a unified computing environment for genomics data storage, management, and analysis. In this perspective, we present AnVIL, describe its ecosystem and interoperability with other platforms, and highlight how this platform and associated initiatives contribute to improved genomic data sharing efforts. The AnVIL is a federated cloud platform designed to manage and store genomics and related data, enable population-scale analysis, and facilitate collaboration through the sharing of data, code, and analysis results. By inverting the traditional model of data sharing, the AnVIL eliminates the need for data movement while also adding security measures for active threat detection and monitoring and provides scalable, shared computing resources for any researcher. We describe the core data management and analysis components of the AnVIL, which currently consists of Terra, Gen3, Galaxy, RStudio/Bioconductor, Dockstore, and Jupyter, and describe several flagship genomics datasets available within the AnVIL. We continue to extend and innovate the AnVIL ecosystem by implementing new capabilities, including mechanisms for interoperability and responsible data sharing, while streamlining access management. The AnVIL opens many new opportunities for analysis, collaboration, and data sharing that are needed to drive research and to make discoveries through the joint analysis of hundreds of thousands to millions of genomes along with associated clinical and molecular data types

From Abstract to Manipulatable – The Hybridization Explorer, A Digital Interactive for Studying Orbitals

The abstract nature of atomic and hybrid orbitals makes it a challenging concept for students to understand. Presented is the Hybridization Explorer, a web-based interactive learning tool, for manipulating and experimenting with hybridization concepts. Through the explorer students can explore both the combination of atomic orbitals, and the visual representation of both atomic and hybrid orbitals and corresponding bond formation. Case studies from an undergraduate and graduate-level demonstration of the explorer are described. Finally, self-reported student confidence levels on solving hybridization questions both before and after use of the explorer are analyzed and discussed.</p

BlockmiR AONs as Site-Specific Therapeutic MBNL Modulation in Myotonic Dystrophy 2D and 3D Muscle Cells and HSA^LR Mice

The symptoms of Myotonic Dystrophy Type 1 (DM1) are multi-systemic and life-threatening. The neuromuscular disorder is rooted in a non-coding CTG microsatellite expansion in the DM1 protein kinase (DMPK) gene that, upon transcription, physically sequesters the Muscleblind-like (MBNL) family of splicing regulator proteins. The high-affinity binding occurring between the proteins and the repetitions disallow MBNL proteins from performing their post-transcriptional splicing regulation leading to downstream molecular effects directly related to disease symptoms such as myotonia and muscle weakness. In this study, we build on previously demonstrated evidence showing that the silencing of miRNA-23b and miRNA-218 can increase MBNL1 protein in DM1 cells and mice. Here, we use blockmiR antisense technology in DM1 muscle cells, 3D mouse-derived muscle tissue, and in vivo mice to block the binding sites of these microRNAs in order to increase MBNL translation into protein without binding to microRNAs. The blockmiRs show therapeutic effects with the rescue of mis-splicing, MBNL subcellular localization, and highly specific transcriptomic expression. The blockmiRs are well tolerated in 3D mouse skeletal tissue inducing no immune response. In vivo, a candidate blockmiR also increases Mbnl1/2 protein and rescues grip strength, splicing, and histological phenotypes

Correlates of Medical Nutrition Therapy and Cardiovascular Outcomes in Youth With Type 1 Diabetes

OBJECTIVE: To examine whether the types of medical nutrition therapies (MNTs) taught to and used by youth with type 1 diabetes (T1D) varies by socio-demographic characteristics and cardiovascular (CVD) risk factors DESIGN: Cross-sectional study SETTING: The SEARCH for Diabetes in Youth study is a population-based cohort of individuals with clinical diagnosed diabetes PARTICIPANTS: 1,191 individuals with T1D MAIN OUTCOME MEASURES: Types of MNTs and frequency of use ANALYSIS: Bivariate analysis and multivariate linear regression (P<0.05) RESULTS: More race/ethnic minorities (vs. whites), individuals with parents <high school education (vs. ≥high school), and overweight/obese (vs. underweight/normal weight) were taught additional MNTs. For underweight/normal weight individuals exclusively taught carbohydrate counting, those who used this approach “often” had lower A1c (8.6 vs. 8.9%) and triglycerides (73.5 vs. 84.1 mg/dL) than those who used it “sometimes/never.” “Often” use of additional MNTs beyond carbohydrate counting was not associated with better mean values for CVD risk factors. CONCLUSIONS AND IMPLICATIONS: In individuals with T1D, race/ethnic minorities, individuals with parents <high school education, and overweight/obese individuals are taught more MNTs. Further research is needed to understand the effectiveness of the various MNTs on CVD risk factors, and identify how to translate nutrition knowledge to behavior and metabolic status

Decadal changes in fire frequencies shift tree communities and functional traits

Global change has resulted in chronic shifts in fire regimes. Variability in the sensitivity of tree communities to multi-decadal changes in fire regimes is critical to anticipating shifts in ecosystem structure and function, yet remains poorly understood. Here, we address the overall effects of fire on tree communities and the factors controlling their sensitivity in 29 sites that experienced multi-decadal alterations in fire frequencies in savanna and forest ecosystems across tropical and temperate regions. Fire had a strong overall effect on tree communities, with an average fire frequency (one fire every three years) reducing stem density by 48% and basal area by 53% after 50 years, relative to unburned plots. The largest changes occurred in savanna ecosystems and in sites with strong wet seasons or strong dry seasons, pointing to fire characteristics and species composition as important. Analyses of functional traits highlighted the impact of fire-driven changes in soil nutrients because frequent burning favoured trees with low biomass nitrogen and phosphorus content, and with more efficient nitrogen acquisition through ectomycorrhizal symbioses. Taken together, the response of trees to altered fire frequencies depends both on climatic and vegetation determinants of fire behaviour and tree growth, and the coupling between fire-driven nutrient losses and plant traits