Publications by authors named "Charlotte Farquhar"

An expansion of the hexanucleotide (GGGGCC) repeat sequence in chromosome 9 open frame 72 () is the most common genetic mutation in amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). The mutation leads to the production of toxic dipeptide repeat proteins (DPRs) that induce neurodegeneration. However, the fundamental physicochemical properties of DPRs remain largely unknown due to their limited availability.

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Peptide-mediated delivery of macromolecules in cells has significant potential therapeutic benefits, but no therapy employing cell-penetrating peptides (CPPs) has reached the market after 30 years of investigation due to challenges in the discovery of new, more efficient sequences. Here, we demonstrate a method for in-cell penetration selection-mass spectrometry (in-cell PS-MS) to discover peptides from a synthetic library capable of delivering macromolecule cargo to the cytosol. This method was inspired by recent selection approaches for cell-surface screening, with an added spatial dimension resulting from subcellular fractionation.

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Peptide-based cancer vaccines are widely investigated in the clinic but exhibit modest immunogenicity. One approach that has been explored to enhance peptide vaccine potency is covalent conjugation of antigens with cell-penetrating peptides (CPPs), linear cationic and amphiphilic peptide sequences designed to promote intracellular delivery of associated cargos. Antigen-CPPs have been reported to exhibit enhanced immunogenicity compared to free peptides, but their mechanisms of action in vivo are poorly understood.

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Background: Glioblastoma (GBM) is the most common and deadliest malignant primary brain tumor, contributing significant morbidity and mortality among patients. As current standard-of-care demonstrates limited success, the development of new efficacious GBM therapeutics is urgently needed. Major challenges in advancing GBM chemotherapy include poor bioavailability, lack of tumor selectivity leading to undesired side effects, poor permeability across the blood-brain barrier (BBB), and extensive intratumoral heterogeneity.

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Carboranes represent a class of compounds with increasing therapeutic potential. However, few general approaches to readily embed carboranes into small molecules, peptides, and proteins are available. We report a strategy based on palladium-mediated C-X (X = C, S, and N) bond formation for the installation of carborane-containing moieties onto small molecules and peptides.

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Article Synopsis
  • * A new automated fast-flow technology enables the efficient production of CPP-conjugated PNAs (PPNAs), making the synthesis process quick and effective.
  • * The study showed that a PPNA targeting SARS-CoV-2 significantly reduced the virus's presence, indicating potential for developing PPNAs as antiviral therapies.
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Cell-penetrating peptides (CPPs) can cross the cell membrane to enter the cytosol and deliver otherwise nonpenetrant macromolecules such as proteins and oligonucleotides. For example, recent clinical trials have shown that a CPP attached to phosphorodiamidate morpholino oligomers (PMOs) resulted in higher muscle concentration, increased exon skipping, and dystrophin production relative to another study of the PMO alone in patients of Duchenne muscular dystrophy. Therefore, effective design and the study of CPPs could help enhance therapies for difficult-to-treat diseases.

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Article Synopsis
  • Glioblastoma multiforme (GBM) is a severe and challenging brain tumor, with Brevican (Bcan) being a key protein that is notably increased in GBM cells.
  • A specific isoform of Bcan, called dg-Bcan, is unique to GBM tissues and is being investigated as a potential target for treatment.
  • Researchers discovered an 8-amino acid peptide, BTP-7, that binds effectively to dg-Bcan and shows promise for use in imaging and targeted therapies for GBM patients.
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Cannabis edibles are becoming more common in an increasingly diverse population of users, and the impact of first pass metabolism on cannabis's pharmacological profile across age and sex is not well understood. The present study examined the impact of age, sex and rodent species on the effects of intraperitoneal (i.p.

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Capture and release of peptides is often a critical operation in the pathway to discovering materials with novel functions. However, the best methods for efficient capture impede facile release. To overcome this challenge, we report linkers based on secondary amino alcohols for the release of peptides after capture.

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Synthetic cannabinoids (SCs) are novel psychoactive substances that are easily acquired, widely abused as a substitute for cannabis, and associated with cardiotoxicity and seizures. Although the structural bases of these compounds are scaffolds with known affinity and efficacy at the human cannabinoid type-1 receptor (hCB), upon ingestion or inhalation they can be metabolized to multiple chemical entities of unknown pharmacological activity. A large proportion of these metabolites are hydroxylated on the pentyl chain, a key substituent that determines receptor affinity and selectivity.

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Background: The recent NIH mandate to consider sex as a biological variable in preclinical research has focused attention on delineation of sex differences in behavior. To investigate mechanisms underlying sex differences in Δ-tetrahydrocannabinol (THC) effects, we examined the effects of sex and gonadal hormones on CB receptors in cerebellum, hippocampus, prefrontal cortex, and striatum.

Methods: Adult Sprague-Dawley rats underwent gonadectomy (GDX) or sham-GDX.

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Allosteric modulators have attracted significant interest as an alternate strategy to modulate CB receptor signaling for therapeutic benefits that may avoid the adverse effects associated with orthosteric ligands. Here we extended our previous structure-activity relationship studies on the diarylurea-based CB negative allosteric modulators (NAMs) by introducing five-membered heterocycles to replace the 5-pyrrolidinylpyridinyl group in PSNCBAM-1 (1), one of the first generation CB allosteric modulators. Many of these compounds had comparable potency to 1 in blocking the CB agonist CP55,940 stimulated calcium mobilization and [S]GTP-γ-S binding.

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Synthetic cannabinoids are a class of novel psychoactive substances that exhibit high affinity at the cannabinoid type-1 (CB) receptor and produce effects similar to those of Δ-9-tetrahydrocannabinol (THC), the primary psychoactive constituent of cannabis. Illicit drug manufacturers are continually circumventing laws banning the sale of synthetic cannabinoids by synthesizing novel structures and doing so with little regard for the potential impact on pharmacological and toxicological effects. Synthetic cannabinoids produce a wide range of effects that include cardiotoxicity, seizure activity, and kidney damage, and they can cause death.

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While allosteric modulators of the cannabinoid type-1 receptor (CB) continue to be developed and characterized, the gap between the in vitro and in vivo data is widening, raising questions regarding translatability of their effects and biological relevance. Among the CB allosteric modulators, PSNCBAM-1 has received little attention regarding its effects in vivo. Recently, pregnenolone was reported to act as an allosteric modulator of CB, blocking THC's effects in vitro and in vivo, highlighting the potential of CB allosteric modulators for treatment of cannabis intoxication.

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Allosteric modulators of the cannabinoid CB1 receptor have recently been reported as an alternative approach to modulate the CB1 receptor for therapeutic benefits. In this study, we report the design and synthesis of a series of diarylureas derived from PSNCBAM-1 (2). Similar to 2, these diarylureas dose-dependently inhibited CP55,940-induced intracellular calcium mobilization and [S]GTP-γ-S binding while enhancing [H]CP55,940 binding to the CB1 receptor.

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