Publications by authors named "Ryan Friedman"

Deep learning is a promising strategy for modeling cis-regulatory elements. However, models trained on genomic sequences often fail to explain why the same transcription factor can activate or repress transcription in different contexts. To address this limitation, we developed an active learning approach to train models that distinguish between enhancers and silencers composed of binding sites for the photoreceptor transcription factor cone-rod homeobox (CRX).

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Purpose: The vocal folds (VFs) are among the most mechanically active connective tissues, vibrating between 80 and 250 hz during speech. Overall VF function is determined by the composition and structure of their extracellular matrix (ECM). During tissue maturation, the VFs remodel from a monolayer of collagen fibers to a tri-layered structure, affecting tissue biomechanics.

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Objective: Pediatric subglottic stenosis (SGS) is characterized by subglottic narrowing which occurs when pathological fibroblasts deposit extracellular matrix that reduces airway patency. Recent clinical observations have suggested that azithromycin may have favorable impacts on SGS reduction while treating airway infections; furthermore, our recent work in mice demonstrated that the airway microbiome influences SGS. In this work, we characterize the protective effect of azithromycin as an immunomodulatory and antibacterial therapeutic against subglottic stenosis.

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Dozens of variants in the gene for the homeodomain transcription factor (TF) cone-rod homeobox () are linked with human blinding diseases that vary in their severity and age of onset. How different variants in this single TF alter its function in ways that lead to a range of phenotypes is unclear. We characterized the effects of human disease-causing variants on CRX -regulatory function by deploying massively parallel reporter assays (MPRAs) in mouse retina explants carrying knock-ins of two variants, one in the DNA-binding domain (p.

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Article Synopsis
  • The activity of cis-regulatory elements (CREs) is influenced by the sequence context of transcription factor binding sites (TFBSs), with the CRX TF playing a key role in rod photoreceptors.
  • CRX sites can positively enhance CRE activity, but multiple CRX sites may lead to repression due to negative interactions between them.
  • The presence of other TFBSs can help mitigate these negative interactions, indicating that a diverse range of TFBSs is needed for enhancers to function effectively.
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The creation of an engineered trachea with robust phenotype and sufficient mechanical properties for clinical application remains a challenge. In their work, Tang et al. propose a stacked approach of alternating cartilaginous and fibrous rings to form a tracheal segment, which integrated and retain patency in rabbits for 8 weeks.

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The function of regulatory elements is highly dependent on the cellular context, and thus for understanding the function of elements associated with psychiatric diseases these would ideally be studied in neurons in a living brain. Massively Parallel Reporter Assays (MPRAs) are molecular genetic tools that enable functional screening of hundreds of predefined sequences in a single experiment. These assays have not yet been adapted to query specific cell types in vivo in a complex tissue like the mouse brain.

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Introduction: Pediatric subglottic stenosis (SGS) results from prolonged intubation where scar tissue leads to airway narrowing that requires invasive surgery. We have recently discovered that modulating the laryngotracheal microbiome can prevent SGS. Herein, we show how our patent-pending antimicrobial peptide-eluting endotracheal tube (AMP-ET) effectively modulates the local airway microbiota resulting in reduced inflammation and stenosis resolution.

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-regulatory elements (CREs) direct gene expression in health and disease, and models that can accurately predict their activities from DNA sequences are crucial for biomedicine. Deep learning represents one emerging strategy to model the regulatory grammar that relates CRE sequence to function. However, these models require training data on a scale that exceeds the number of CREs in the genome.

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Objective: Subglottic stenosis (SGS) may result from prolonged intubation where fibrotic scar tissue narrows the airway. The scar forms by differentiated myofibroblasts secreting excessive extracellular matrix (ECM). TGF-β1 is widely accepted as a regulator of fibrosis; however, it is unclear how biomechanical pathways co-regulate fibrosis.

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Dozens of variants in the photoreceptor-specific transcription factor (TF) CRX are linked with human blinding diseases that vary in their severity and age of onset. It is unclear how different variants in this single TF alter its function in ways that lead to a range of phenotypes. We examined the effects of human disease-causing variants on CRX -regulatory function by deploying massively parallel reporter assays (MPRAs) in live mouse retinas carrying knock-ins of two variants, one in the DNA binding domain (p.

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Article Synopsis
  • Enhancers and silencers share similar transcription factors, which can lead to confusion in genomic studies.
  • Researchers studied how different DNA sequences in mouse retinas, influenced by the transcription factor CRX, vary between enhancers and silencers.
  • They found that enhancers have a higher diversity and number of transcription factor motifs compared to silencers, indicating that the context of these motifs plays a crucial role in their regulatory activity.
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Following publication of the original paper [1], an error was reported in the processing of Fig. 2. The correct Fig.

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Background: Transposable elements (TEs) make up half of mammalian genomes and shape genome regulation by harboring binding sites for regulatory factors. These include binding sites for architectural proteins, such as CTCF, RAD21, and SMC3, that are involved in tethering chromatin loops and marking domain boundaries. The 3D organization of the mammalian genome is intimately linked to its function and is remarkably conserved.

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Objective: Common data elements (CDEs) promote data sharing, standardization, and uniform data collection, which facilitate meta-analyses and comparisons of studies. Currently, there is no set of CDEs for all trauma populations, but their creation would allow researchers to leverage existing databases to maximize research on trauma outcomes. The purpose of this study is to assess the extent of common data collection among 5 trauma databases.

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Received wisdom in the field of fungal biology holds that the process of editing a genome by transformation and homologous recombination is inherently mutagenic. However, that belief is based on circumstantial evidence. We provide the first direct measurement of the effects of transformation on a fungal genome by sequencing the genomes of 29 transformants and 30 untransformed controls with high coverage.

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