960 results match your criteria: "Donnelly Centre for Cellular and Biomolecular Research[Affiliation]"

Brilacidin, a novel antifungal agent against .

mBio

July 2024

Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, Brazil.

Unlabelled: causes cryptococcosis, one of the most prevalent fungal diseases, generally characterized by meningitis. There is a limited and not very effective number of drugs available to combat this disease. In this manuscript, we show the host defense peptide mimetic brilacidin (BRI) as a promising antifungal drug against .

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Viscoelastic Supramolecular Hyaluronan-Peptide Cross-Linked Hydrogels.

Biomacromolecules

July 2024

Department of Biomedical Engineering, University of Toronto, Toronto, Ontario M5S 1A1, Canada.

Viscoelasticity plays a key role in hydrogel design. We designed a physically cross-linked hydrogel with tunable viscoelasticity, comprising supramolecular-assembled peptides coupled to hyaluronan (HA), a native extracellular matrix component. We then explored the structural and molecular mechanisms underlying the mechanical properties of a series of these HA-peptide hydrogels.

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Get your receptors in a knot with new Wnt signaling agonists.

Cell Chem Biol

June 2024

Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, ON, Canada; Leslie Dan Faculty of Pharmacy and Department of Biochemistry, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada. Electronic address:

Pharmacological modulation of the Wnt/β-catenin signaling pathway holds promises for both basic research and therapeutic applications. In this issue of Cell Chemical Biology, Kschonsak et al. engineered knotted peptides that promote Wnt signaling by targeting ZNRF3 and serve as pharmacological tools for studying Wnt biology and supporting organoid growth.

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K29-linked free polyubiquitin chains affect ribosome biogenesis and direct ribosomal proteins to the intranuclear quality control compartment.

Mol Cell

June 2024

Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, 160 College Street, Toronto, ON M5S 3E1, Canada; Department of Molecular Genetics, University of Toronto, 160 College Street, Toronto, ON M5S 3E1, Canada. Electronic address:

Ribosome assembly requires precise coordination between the production and assembly of ribosomal components. Mutations in ribosomal proteins that inhibit the assembly process or ribosome function are often associated with ribosomopathies, some of which are linked to defects in proteostasis. In this study, we examine the interplay between several yeast proteostasis enzymes, including deubiquitylases (DUBs) Ubp2 and Ubp14, and E3 ligases Ufd4 and Hul5, and we explore their roles in the regulation of the cellular levels of K29-linked unanchored polyubiquitin (polyUb) chains.

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Astrocytes that reside in superficial (SL) and deep cortical layers have distinct molecular profiles and morphologies, which may underlie specific functions. Here, we demonstrate that the production of SL and deep layer (DL) astrocyte populations from neural progenitor cells in the mouse is temporally regulated. Lineage tracking following in utero and postnatal electroporation with PiggyBac (PB) EGFP and birth dating with EdU and FlashTag, showed that apical progenitors produce astrocytes during late embryogenesis (E16.

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Proteins and nucleic-acids are essential components of living organisms that interact in critical cellular processes. Accurate prediction of nucleic acid-binding residues in proteins can contribute to a better understanding of protein function. However, the discrepancy between protein sequence information and obtained structural and functional data renders most current computational models ineffective.

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Bridging the gap between in vitro and in vivo models: a way forward to clinical translation of mitochondrial transplantation in acute disease states.

Stem Cell Res Ther

May 2024

Department of Pharmacology and Toxicology, University of Toronto, Medical Science Building, Room 4211, 1 King's College Circle, Toronto, ON, M5S 1A8, Canada.

Mitochondrial transplantation and transfer are being explored as therapeutic options in acute and chronic diseases to restore cellular function in injured tissues. To limit potential immune responses and rejection of donor mitochondria, current clinical applications have focused on delivery of autologous mitochondria. We recently convened a Mitochondrial Transplant Convergent Working Group (CWG), to explore three key issues that limit clinical translation: (1) storage of mitochondria, (2) biomaterials to enhance mitochondrial uptake, and (3) dynamic models to mimic the complex recipient tissue environment.

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Detecting nucleic acids at ultralow concentrations is critical for research and clinical applications. Particle-based assays are commonly used to detect nucleic acids. However, DNA hybridization on particle surfaces is inefficient due to the instability of tethered sequences, which negatively influences the assay's detection sensitivity.

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HelixDiff, a Score-Based Diffusion Model for Generating All-Atom α-Helical Structures.

ACS Cent Sci

May 2024

Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario M5S 3E1, Canada.

Article Synopsis
  • HelixDiff is a new score-based diffusion model designed to create all-atom helical structures, specifically tuning α-helices for crucial residues in bioactive peptides.
  • The model demonstrates high accuracy, generating α-helices with minimal deviations from native structures (less than 1 Å) and outperforming previous models in sequence recovery and quality.
  • As a practical application, HelixDiff was used to design a stable D-peptide agonist that activates the GLP-1 receptor without affecting the GLP-2 receptor, showing that key residue matching is more critical than the sequence's orientation for effectiveness.
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Mechanisms and Barriers in Nanomedicine: Progress in the Field and Future Directions.

ACS Nano

June 2024

Department of Pharmaceutical Sciences, The Skaggs School of Pharmacy and Pharmaceutical Sciences, the University of Colorado Anschutz Medical Campus, Aurora, Colorado 80045, United States.

In recent years, steady progress has been made in synthesizing and characterizing engineered nanoparticles, resulting in several approved drugs and multiple promising candidates in clinical trials. Regulatory agencies such as the Food and Drug Administration and the European Medicines Agency released important guidance documents facilitating nanoparticle-based drug product development, particularly in the context of liposomes and lipid-based carriers. Even with the progress achieved, it is clear that many barriers must still be overcome to accelerate translation into the clinic.

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Hyaluronan improves photoreceptor differentiation and maturation in human retinal organoids.

Acta Biomater

June 2024

Terrence Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Canada; Institute of Biomedical Engineering, University of Toronto, Canada; Department of Chemical Engineering and Applied Chemistry, University of Toronto, Canada; Department of Chemistry, University of Toronto, Canada. Electronic address:

Human stem cell-derived organoids enable both disease modeling and serve as a source of cells for transplantation. Human retinal organoids are particularly important as a source of human photoreceptors; however, the long differentiation period required and lack of vascularization in the organoid often results in a necrotic core and death of inner retinal cells before photoreceptors are fully mature. Manipulating the in vitro environment of differentiating retinal organoids through the incorporation of extracellular matrix components could influence retinal development.

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MassDash: A Web-Based Dashboard for Data-Independent Acquisition Mass Spectrometry Visualization.

J Proteome Res

June 2024

Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, Ontario M5S 3E1, Canada.

With the increased usage and diversity of methods and instruments being applied to analyze Data-Independent Acquisition (DIA) data, visualization is becoming increasingly important to validate automated software results. Here we present MassDash, a cross-platform DIA mass spectrometry visualization and validation software for comparing features and results across popular tools. MassDash provides a web-based interface and Python package for interactive feature visualizations and summary report plots across multiple automated DIA feature detection tools, including OpenSwath, DIA-NN, and dreamDIA.

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Drug dependence is characterized by a switch in motivation wherein a positively reinforcing substance can become negatively reinforcing. Put differently, drug use can transform from a form of pleasure-seeking to a form of relief-seeking. Ventral tegmental area (VTA) GABA neurons form an anatomical point of divergence between two double dissociable pathways that have been shown to be functionally implicated and necessary for these respective motivations to seek drugs.

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Recent advances in single-cell sequencing technology have provided opportunities for mathematical modeling of dynamic developmental processes at the single-cell level, such as inferring developmental trajectories. Optimal transport has emerged as a promising theoretical framework for this task by computing pairings between cells from different time points. However, optimal transport methods have limitations in capturing nonlinear trajectories, as they are static and can only infer linear paths between endpoints.

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Validation of the 2022 European LeukemiaNet risk stratification for acute myeloid leukemia.

Sci Rep

April 2024

Department of Medical Oncology and Hematology, Princess Margaret Cancer Centre, University of Toronto, Toronto, Canada.

This study aimed to validate the 2022 European LeukemiaNet (ELN) risk stratification for acute myeloid leukemia (AML). A total of 624 newly diagnosed AML patients from 1998 to 2014 were included in the analysis. Genetic profiling was conducted using targeted deep sequencing of 45 genes based on recurrent driver mutations.

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Identifying human pre-mRNA cleavage and polyadenylation factors by genome-wide CRISPR screens using a dual fluorescence readthrough reporter.

Nucleic Acids Res

May 2024

Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, 160 College Street, Toronto, ON M5S 3E1, Canada.

Messenger RNA precursors (pre-mRNA) generally undergo 3' end processing by cleavage and polyadenylation (CPA), which is specified by a polyadenylation site (PAS) and adjacent RNA sequences and regulated by a large variety of core and auxiliary CPA factors. To date, most of the human CPA factors have been discovered through biochemical and proteomic studies. However, genetic identification of the human CPA factors has been hampered by the lack of a reliable genome-wide screening method.

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Progression through the G1 phase of the cell cycle is the most highly regulated step in cellular division. We employed a chemogenetic approach to discover novel cellular networks that regulate cell cycle progression. This approach uncovered functional clusters of genes that altered sensitivity of cells to inhibitors of the G1/S transition.

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Stroke is the leading cause of adult disability worldwide. The majority of stroke survivors are left with devastating functional impairments for which few treatment options exist. Recently, a number of studies have used ectopic expression of transcription factors that direct neuronal cell fate with the intention of converting astrocytes to neurons in various models of brain injury and disease.

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Numerous studies have demonstrated the correlation between human gut bacteria and host physiology, mediated primarily via nuclear receptors (NRs). Despite this body of work, the systematic identification and characterization of microbe-derived ligands that regulate NRs remain a considerable challenge. In this study, we discover a series of diindole molecules produced from commensal bacteria metabolites that act as specific agonists for the orphan constitutive androstane receptor (CAR).

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Gene regulatory networks (GRNs) involve complex and multi-layer regulatory interactions between regulators and their target genes. Precise knowledge of GRNs is important in understanding cellular processes and molecular functions. Recent breakthroughs in single-cell sequencing technology made it possible to infer GRNs at single-cell level.

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Targeted protein degradation and stabilization are promising therapeutic modalities because of their potency, versatility and their potential to expand the druggable target space. However, only a few of the hundreds of E3 ligases and deubiquitinases in the human proteome have been harnessed for this purpose, which substantially limits the potential of the approach. Moreover, there may be other protein classes that could be exploited for protein stabilization or degradation, but there are currently no methods that can identify such effector proteins in a scalable and unbiased manner.

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Background: The discovery of material transfer between transplanted and host mouse photoreceptors has expanded the possibilities for utilizing transplanted photoreceptors as potential vehicles for delivering therapeutic cargo. However, previous research has not directly explored the capacity for human photoreceptors to engage in material transfer, as human photoreceptor transplantation has primarily been investigated in rodent models of late-stage retinal disease, which lack host photoreceptors.

Methods: In this study, we transplanted human stem-cell derived photoreceptors purified from human retinal organoids at different ontological ages (weeks 10, 14, or 20) into mouse models with intact photoreceptors and assessed transfer of human proteins and organelles to mouse photoreceptors.

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Proteome-scale movements and compartment connectivity during the eukaryotic cell cycle.

Cell

March 2024

Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, ON M5S 3E1, Canada; Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 1A8, Canada. Electronic address:

Cell cycle progression relies on coordinated changes in the composition and subcellular localization of the proteome. By applying two distinct convolutional neural networks on images of millions of live yeast cells, we resolved proteome-level dynamics in both concentration and localization during the cell cycle, with resolution of ∼20 subcellular localization classes. We show that a quarter of the proteome displays cell cycle periodicity, with proteins tending to be controlled either at the level of localization or concentration, but not both.

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Gemcitabine is a potent inhibitor of DNA replication and is a mainstay therapeutic for diverse cancers, particularly pancreatic ductal adenocarcinoma (PDAC). However, most tumors remain refractory to gemcitabine therapies. Here, to define the cancer cell response to gemcitabine, we performed genome-scale CRISPR-Cas9 chemical-genetic screens in PDAC cells and found selective loss of cell fitness upon disruption of the cytidine deaminases APOBEC3C and APOBEC3D.

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Advancements in genomics are transforming the clinical management of chronic myeloid leukemia (CML) toward precision medicine. The impact of somatic mutations on treatment outcomes is still under debate. We studied the association of somatic mutations in epigenetic modifier genes and activated signaling/myeloid transcription factors (AS/MTFs) with disease progression and treatment failure in patients with CML after tyrosine kinase inhibitor (TKI) therapy.

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