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In utero rescue of neurological dysfunction in a mouse model of Wiedemann-Steiner syndrome.
No full textWiedemann-Steiner syndrome (WDSTS) is a rare genetic cause of intellectual disability that is primarily caused by heterozygous loss-of-function variants in the gene encoding the histone lysine methyltransferase 2A (KMT2A). Prior studies have shown successful postnatal amelioration of disease phenotypes for Rett, Rubinstein-Taybi, and Kabuki syndromes, which are related Mendelian disorders of the epigenetic machinery. To explore whether the neurological phenotype in WDSTS is treatable in utero, we created a mouse model carrying a loss-of-function variant placed between 2 loxP sites. Kmt2a+/LSL mice demonstrated core features of WDSTS including growth retardation, craniofacial abnormalities, and hypertrichosis as well as hippocampal memory defects. The neurological phenotypes were rescued upon restoration of KMT2A in utero following breeding to a nestin-Cre. Together, our data provide a mouse model to explore the potential therapeutic window in WDSTS. Our work suggests that WDSTS has a window of opportunity extending at least until the midpoint of in utero development, making WDSTS an ideal candidate for future therapeutic strategies
Genetic and epigenetic screens in primary human T cells link candidate causal autoimmune variants to T cell networks.
No full textGenetic variants associated with autoimmune diseases are highly enriched within putative cis-regulatory regions of CD4+ T cells, suggesting that they could alter disease risk through changes in gene regulation. However, very few genetic variants have been shown to affect T cell gene expression or function. Here we tested \u3e18,000 autoimmune disease-associated variants for allele-specific effects on expression using massively parallel reporter assays in primary human CD4+ T cells. We find 545 variants that modulate expression in an allele-specific manner (emVars). Primary T cell emVars greatly enrich for likely causal variants, are mediated by common upstream pathways and their putative target genes are highly enriched within a lymphocyte activation network. Using bulk and single-cell CRISPR-interference screens, we confirm that emVar-containing T cell cis-regulatory elements modulate both known and previously unappreciated target genes that regulate T cell proliferation, providing plausible mechanisms by which these variants alter autoimmune disease risk
The recombinant zoster vaccine induces trained immunity in monocytes through persistent downregulation of TGFβ.
No full textOlder adults have decreased vaccine efficacy, but the adjuvanted recombinant VZV-gE zoster vaccine (RZV) is highly efficacious. We investigated memory-like innate immune responses after RZV and after the zoster vaccine live (ZVL), which is much less efficacious. RZV increased NK, monocyte, and DC activation in response to in vitro VZV-gE stimulation for up to 5 years post-vaccination, while ZVL increased only DC responses to VZV for up to 90 days. In purified monocyte and NK cell cocultures, RZV recipients showed increased responses to VZV-gE, HCMV and HSV antigenic stimulation post-vaccination. ATAC-seq analysis of purified monocytes revealed decreased accessibility in areas of the TGFβ1 gene. scRNA-seq and immunoproteomics confirmed decreased TGFβ1 transcription and translation, respectively. Exogenous supplementation and inhibition of TGFβ1 modulated in vitro monocyte responses to VZV-gE. In conclusion, RZV generated homologous (VZV-gE) and heterologous (HCMV, HSV) trained immunity in monocytes through genomic repression of the regulatory cytokine TGFβ-1. Cytokine modulation may represent a novel mechanism of generating trained immunity in myeloid cells
Planar polarized organization of mouse hair cells is established and maintained by STK32A, GPR156 and EMX2.
No full textHair cells in the utricle and saccule form two groups with oppositely oriented stereociliary bundles that enable detection of broad ranges of motion. These groups are aligned along a common polarity axis established by core planar cell polarity (PCP) proteins, which individual cells interpret differently to generate opposing bundle orientations. EMX2, GPR156 and STK32A determine how these groups integrate PCP signaling during this process. We tested functional interactions between these factors using genetic epistasis experiments and evaluating hair cells in mice with combined mutations in Gpr156 and Stk32a or Emx2 and Stk32a. We show in the utricle that: (1) GPR156 functions to reverse stereociliary bundles relative to the PCP axis but can be blocked by STK32A; and (2) EMX2 establishes the boundary between the two groups by repressing Stk32a transcription. We further demonstrate that these factors have similar functional relationships in the cochlea, despite the absence of polarity reversal in that tissue. Together, these phenotypes support a mechanism whereby EMX2 regulates Stk32a transcription, thereby allowing GPR156 to reverse the orientation of stereociliary bundles in one group of hair cells
Integrated phenotypic and proteomic screening identifies top-tier Alzheimer\u27s disease therapeutic targets.
No full textINTRODUCTION: Alzheimer\u27s disease (AD) is a complex neurodegenerative disorder. Hundreds of therapeutic targets have been nominated through genetic and multi-omic studies, but effective prioritization remains a major bottleneck.
METHODS: We applied an integrative screening framework to assess 29 candidate targets from risk-enriched biological domains. Using disease-relevant murine BV2 microglial cell lines with stable Psen2 knockdown, we performed small interfering RNA-mediated perturbations followed by cellular phenotypic assays and quantitative proteomics.
RESULTS: Twenty-five candidate targets significantly altered at least one phenotype, with stronger effects in Psen2 knockdown cells. Integrated proteomic analyses identified several perturbations that reversed AD-associated molecular patterns. Five targets-Ap2a2, Pdhb, Pdha1, Dlat, and Psmc3-impacted both phenotypes and related proteomic responses.
DISCUSSION: We established a scalable platform for target functional validation that bridges unbiased systems-level assessments of AD risk with experimental evidence. The Emory-Sage-Structural Genomics Consortium-Jax Center Target Enablement to Accelerate Therapy Development for Alzheimer\u27s Disease center will prioritize further resource development for these validated targets.
HIGHLIGHTS: A screening platform was created to identify the most potent targets from nominated hypotheses. Integrated analysis of cellular proteomics and assay phenotypes was performed. Targets capable of reversing disease-associated proteomic signal were identified. The most impactful targets were strongly implicated in Alzheimer\u27s disease pathogenesis
An ontology-based rare disease common data model harmonising international registries, FHIR, and Phenopackets.
Full text linkAlthough rare diseases (RDs) affect over 260 million individuals worldwide, low data quality and scarcity challenge effective care and research. This work aims to harmonise the Common Data Set by European Rare Disease Registry Infrastructure, Health Level 7 Fast Healthcare Interoperability Base Resources, and the Global Alliance for Genomics and Health Phenopacket Schema into a novel rare disease common data model (RD-CDM), laying the foundation for developing international RD-CDMs aligned with these data standards. We developed a modular-based GitHub repository and documentation to account for flexibility, extensions and further development. Recommendations on the model\u27s cardinalities are given, inviting further refinement and international collaboration. An ontology-based approach was selected to find a common denominator between the semantic and syntactic data standards. Our RD-CDM version 2.0.0 comprises 78 data elements, extending the ERDRI-CDS by 62 elements with previous versions implemented in four German university hospitals capturing real world data for development and evaluation. We identified three categories for evaluation: Medical Data Granularity, Clinical Reasoning and Medical Relevance, and Interoperability and Harmonisation
Extravillous trophoblasts reverse the decidualization induced increase in matrix production by secreting TGFβ antagonists Emilin-1 and Gremlin-1.
No full textThe maternal-fetal interface has long been considered as a frontier for an evolutionary arms race due to the close juxtaposition of genetically distinct tissues. In hemochorial species with deep placental invasion, including in humans, maternal stroma prepares its defenses against deep trophoblast invasion by decidualization, a differentiation process characterized by increased stromal cell matrix production, and contractile force generation. Decidualization has evolved from an ancestral wound healing response of fibroblast activation by the endometrial stroma. On the placental side, a new trophoblast cell type in great apes has recently evolved, called extravillous trophoblast (EVT), with an exceptionally high invasive capability. Using HTR8, and differentiated EVTs from trophectodermal stem cells, we show that EVTs partly counter decidual myofibroblast activation derived defenses. This reversal in decidual defenses is achieved by secreted antagonists of Transforming Growth Factor β/Bone morphogenic pathway, specifically Emilin-1 and Gremlin-1. Emilin-1 and Gremlin-1 reverse TGFβ activation in decidual cells, reducing high collagen production, and expression of genes associated with myofibroblast transformation. We also show that these secreted TGFβ antagonists can functionally reverse acquired decidual resistance to trophoblast invasion. As our work highlights new mechanisms evolved by trophoblasts to regulate stromal invasibility, it has broader implications in other invasive processes, including wound healing, and cancer metastasis
Ischemic Conditioning Promotes Transneuronal Survival and Stroke Recovery via CD36-Mediated Efferocytosis.
No full textBACKGROUND: Remote ischemic conditioning (RIC) has been implicated in cross-organ protection in cerebrovascular disease, including stroke. However, the lack of a consensus protocol and controversy over the clinical therapeutic outcomes of RIC suggest an inadequate mechanistic understanding of RIC. The current study identifies RIC-induced molecular and cellular events in the blood, which enhance long-term functional recovery in experimental cerebral ischemia.
METHODS: Naive mice or mice subjected to transient ischemic stroke were randomly selected to receive sham conditioning or RIC in the hindlimb at 2 hours post-stroke. At 3 days post-stroke, monocyte composition in the blood was analyzed, and brain tissue was examined for monocyte-derived macrophage (Mφ), levels of efferocytosis, and CD36 expression. Mouse with a specific deletion of CD36 in monocytes/Mφs was used to establish the role of CD36 in RIC-mediated modulation of efferocytosis, transneuronal degeneration, and recovery following stroke.
RESULTS: RIC applied 2 hours after stroke increased the entry of monocytes into the injured brain. In the postischemic brain, Mφ had increased levels of CD36 expression and efferocytosis. These changes in brain Mφ were derived from RIC-induced changes in circulating monocytes. In the blood, RIC increased CD36 expression in circulating monocytes and shifted monocytes to a proinflammatory Lymphocyte antigen 6 complex (LY6C)
CONCLUSIONS: RIC induces a shift in monocytes to a proinflammatory state with elevated CD36 levels, and this is associated with CD36-dependent efferocytosis in Mφs that rescues delayed transneuronal degeneration in the postischemic brain and promotes stroke recovery. Together, these findings provide novel insight into our mechanistic understanding of how RIC improves poststroke recovery
MIDRC mRALE Mastermind Grand Challenge: AI to predict COVID severity on chest radiographs.
Full text linkPURPOSE: The Medical Imaging and Data Resource Center (MIDRC) mRALE Mastermind Grand Challenge fostered the development of artificial intelligence (AI) techniques for the automated assignment of mRALE (modified radiographic assessment of lung edema) scores to portable chest radiographs from patients known to have COVID-19.
APPROACH: The challenge utilized 2079 training cases obtained from the publicly available MIDRC data commons, with validation and test cases sampled from not-yet-public MIDRC cases that were inaccessible to challenge participants. The reference standard mRALE scores for the challenge cases were established by a pool of 22 radiologist annotators. Using the MedICI challenge platform, participants submitted their trained algorithms encapsulated in Docker containers. Algorithms were evaluated by the challenge organizers on 814 test cases through two performance assessment metrics: quadratic-weighted kappa and prediction probability concordance.
RESULTS: Nine AI algorithms were submitted to the challenge for assessment against the test set cases. The algorithm that demonstrated the highest agreement with the reference standard had a quadratic-weighted kappa of 0.885 and a prediction probability concordance of 0.875. Substantial variability in mRALE scores assigned by the annotators and output by the AI algorithms was observed.
CONCLUSIONS: The MIDRC mRALE Mastermind Grand Challenge revealed the potential of AI to assess COVID-19 severity from portable CXRs, demonstrating promising performance against the reference standard. The observed variability in mRALE scores highlights the challenges in standardizing severity assessment. These findings contribute to ongoing efforts to develop AI technologies for potential use in clinical practice and offer insights for the enhancement of COVID-19 severity assessment
Melanocortin 4 Receptor-Dependent Mechanism of ACTH in Preventing Anxiety-Like Behaviors and Normalizing Astrocyte Proteins after Early Life Seizures.
Full text linkEpilepsy, affecting millions globally, often leads to significant cognitive and psychiatric comorbidities, particularly in children. Anxiety and depression are particularly prevalent, with roughly a quarter of pediatric epilepsy patients having a comorbid diagnosis. Current treatments inadequately address these issues. Adrenocorticotropic hormone (ACTH), a melanocortin peptide, has shown promise in mitigating deficits after early-life seizures (ELS), potentially through mechanisms beyond its canonical action on the melanocortin 2 receptor. This study explores the hypothesis that recurrent ELS is associated with long-term anxiety and that treatment with ACTH can prevent this anxiety through a mechanism that involves the melanocortin 4 receptor (MC4R) in the brain. Our findings reveal that ACTH ameliorates anxiety-like behavior associated with ELS, without altering seizure parameters, in wild-type but not in male and female MC4R knock-out mice. Our findings also show that knocking-in MC4R in either neurons or astrocytes was able to rescue the anxiety-like behavior after ACTH treatment. Furthermore, our results show that ACTH normalizes important astrocytic proteins like glial fibrillary acidic protein and aquaporin-4 after ELS. This suggests that ACTH\u27s beneficial effects on anxiety are mediated through MC4R activation in both neuronal and astrocytic populations. This study underscores the therapeutic potential of targeting MC4R as a treatment, highlighting its role in mitigating anxiety-like behaviors associated with ELS