Widespread occurrence of chromosomal aneuploidy following the routine production of Candida albicans mutants

It has come to our attention that approximately 35% of >100 published microarray datasets, where transcript levels were compared between two different strains, exhibit some form of chromosome-specific bias. While some of these arose from the use of strains whose aneuploidies were not known at the time, in a worrisome number of cases the recombinant strains have acquired additional aneuploidies that were not initially present in the parental strain. The aneuploidies often affected a different chromosome than the one harboring the insertion site. The affected strains originated from either CAI-4, RM1000, BWP17 or SN95 and were produced through a variety of strategies. These observations suggest that aneuploidies frequently occur during the production of recombinant strains and have an effect on global transcript profiles outside of the afflicted chromosome(s), thus raising the possibility of unintended phenotypic consequences. Thus, we propose that all Candida albicans mutants and strains should be tested for aneuploidy before being used in further studies. To this end, we describe a new rapid testing method, based on a multiplex quantitative PCR assay, that produces eight bands of distinct sizes from either the left or right arms of each C. albicans chromosome

Fundam Clin Pharmacol

BACKGROUND: Due to its psychoactive effects, ketamine has become a drug used for non-medical purpose. OBJECTIVES: To assess the latest trends in ketamine use among people with substance use disorder and to characterize its clinical complications using complementary health data sources of the French Addictovigilance Network. METHODS: First, we extracted all reports involving ketamine from 2012 to 2021 from the database of the OPPIDUM program (i.e., a multicentric program conducted in collaboration with hundreds of substance abuse treatment facilities that collects data on drugs used by subjects with substance use disorders). We described the reports globally and the changes from 2012 to 2021. Second, we extracted all cases involving ketamine from July 2020 to December 2022 from the French National Pharmacovigilance Database (BNPV). We identified the cases related to ketamine use among people with substance use disorder and described them. RESULTS: There was a 2.5-fold increase in the number of ketamine users with substance use disorder in the OPPIDUM program, from 35 (0.7%) subjects in 2012 to 89 (1.7%) subjects in 2021. There was an increase in the proportion of subjects who were daily users, had distress upon discontinuation, and presented addiction. There were 238 cases related to ketamine use among people with substance use disorder in the French National Pharmacovigilance Database from July 2020 to December 2022. Among them, 94 (39.5%) cases involved ketamine use disorder, 20 (8.4%) cases involved urinary tract and kidney symptoms, and 13 (5.5%) cases involved hepatobiliary symptoms. CONCLUSION: The trend observed over 10 years reflects the growth in ketamine use among people with substance use disorder, although it does not allow to estimate the rates of non-medical use of ketamine in the general population. Ketamine-induced uropathy and cholangiopathy are reported in ketamine users with substance use disorder, especially in case of repeated and/or prolonged use of high doses

Functional and Molecular Characterization of Hedgehog Signalling Regulation

Hedgehog (Hh) signalling plays a key role in controlling cell fate and patterning of tissues during development and also throughout adulthood for tissue homeostasis. The physiological importance of this pathway is further highlighted when mutations in Hh pathway components lead to developmental disorders and diseases: defects of the limbs, cranial structure or nervous system, and cancer in adults. Although the pathway is highly conserved between flies and humans, important divergences exist between them, including the necessity for Sufu to negatively regulate the Gli transcription factors, thought to mediate all Hedgehog transcriptional outputs. The first study presented in this thesis describes Zfp629, a new transcription factor first identified as a novel interactor of Sufu through a proteomics study. ChIP-seq analysis and validation confirmed that Zfp629 controlled the expression of Foxp2. Also a member of this pathway is Smoothened (Smo), a class F G-protein coupled receptor (GPCR). Several inhibitors have already been introduced to treat Hh-driven cancers such as medulloblastoma and basal cell carcinoma. However, resistance to these inhibitors rapidly develops thereby limiting their efficacy. The determination of SMO crystal structures enables structure-based discovery of new ligands with new chemotypes that will be critical to combat resistance. In the second study of this thesis, we docked 3.2 million available, lead-like molecules against SMO, looking for those with high physical complementarity to its structure; this represents the first such campaign against a class F GPCR. Twenty-one high-ranking compounds were selected for experimental testing, and four, representing three different chemotypes, were identified to antagonize SMO with IC50 values better than 50 μM. A second screen for analogs revealed another six molecules, with IC50 values in the 2.3 μM-22.4 μM range. Importantly, one of the most active of the new Smo antagonists continued to be efficacious against the D473H mutant of SMO, which confers clinical resistance to the antagonist vismodegib in cancer treatment.Ph.D

The Spatial Morphology of the Secondary Emission in the Galactic Center Gamma-Ray Excess

Excess GeV gamma rays from the Galactic Center (GC) have been measured with the Fermi Large Area Telescope (LAT). The presence of the GC excess (GCE) appears to be robust with respect to changes in the diffuse galactic background modeling. The three main proposals for the GCE are an unresolved population of millisecond pulsars (MSPs), outbursts of cosmic rays from the GC region, and self-annihilating dark matter (DM). The injection of secondary electrons and positrons into the interstellar medium (ISM) by an unresolved population of MSPs or DM annihilations can lead to observable gamma-ray emission via inverse Compton scattering or bremsstrahlung. Here, we investigate how to determine whether secondaries are important in a model for the GCE. We develop a method of testing model fit which accounts for the different spatial morphologies of the secondary emission. We examine several models which give secondary emission and illustrate a case where a broadband analysis is not sufficient to determine the need for secondary emission

Identification of Novel Smoothened Ligands Using Structure-Based Docking.

The seven transmembrane protein Smoothened is required for Hedgehog signaling during embryonic development and adult tissue homeostasis. Inappropriate activation of the Hedgehog signalling pathway leads to cancers such as basal cell carcinoma and medulloblastoma, and Smoothened inhibitors are now available clinically to treat these diseases. However, resistance to these inhibitors rapidly develops thereby limiting their efficacy. The determination of Smoothened crystal structures enables structure-based discovery of new ligands with new chemotypes that will be critical to combat resistance. In this study, we docked 3.2 million available, lead-like molecules against Smoothened, looking for those with high physical complementarity to its structure; this represents the first such campaign against the class Frizzled G-protein coupled receptor family. Twenty-one high-ranking compounds were selected for experimental testing, and four, representing three different chemotypes, were identified to antagonize Smoothened with IC50 values better than 50 μM. A screen for analogs revealed another six molecules, with IC50 values in the low micromolar range. Importantly, one of the most active of the new antagonists continued to be efficacious at the D473H mutant of Smoothened, which confers clinical resistance to the antagonist vismodegib in cancer treatment

Off the beaten path : novel mRNA-nanoformulations for therapeutic vaccination against HIV

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