A recurrent de novo MAX p.Arg60Gln variant causes a syndromic overgrowth disorder through differential expression of c-Myc target genes.

Cyclin D2 (CCND2) stabilization underpins a range of macrocephaly-associated disorders through mutation of CCND2 or activating mutations in upstream genes encoding PI3K-AKT pathway components. Here, we describe three individuals with overlapping macrocephaly-associated phenotypes who carry the same recurrent de novo c.179G>A (p.Arg60Gln) variant in Myc-associated factor X (MAX). The mutation, located in the b-HLH-LZ domain, causes increased intracellular CCND2 through increased transcription but it does not cause stabilization of CCND2. We show that the purified b-HLH-LZ domain of MAXArg60Gln (Max∗Arg60Gln) binds its target E-box sequence with a lower apparent affinity. This leads to a more efficient heterodimerization with c-Myc resulting in an increase in transcriptional activity of c-Myc in individuals carrying this mutation. The recent development of Omomyc-CPP, a cell-penetrating b-HLH-LZ-domain c-Myc inhibitor, provides a possible therapeutic option for MAXArg60Gln individuals, and others carrying similar germline mutations resulting in dysregulated transcriptional c-Myc activity.

Elpistostege and the origin of the vertebrate hand.

The evolution of fishes to tetrapods (four-limbed vertebrates) was one of the most important transformations in vertebrate evolution. Hypotheses of tetrapod origins rely heavily on the anatomy of a few tetrapod-like fish fossils from the Middle and Late Devonian period (393-359 million years ago)1. These taxa-known as elpistostegalians-include Panderichthys2, Elpistostege3,4 and Tiktaalik1,5, none of which has yet revealed the complete skeletal anatomy of the pectoral fin. Here we report a 1.57-metre-long articulated specimen of Elpistostege watsoni from the Upper Devonian period of Canada, which represents-to our knowledge-the most complete elpistostegalian yet found. High-energy computed tomography reveals that the skeleton of the pectoral fin has four proximodistal rows of radials (two of which include branched carpals) as well as two distal rows that are organized as digits and putative digits. Despite this skeletal pattern (which represents the most tetrapod-like arrangement of bones found in a pectoral fin to date), the fin retains lepidotrichia (fin rays) distal to the radials. We suggest that the vertebrate hand arose primarily from a skeletal pattern buried within the fairly typical aquatic pectoral fin of elpistostegalians. Elpistostege is potentially the sister taxon of all other tetrapods, and its appendages further blur the line between fish and land vertebrates.

Author Correction: Elpistostege and the origin of the vertebrate hand.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Sleep Apnea is Not an Obstacle for Outpatient Hip and Knee Arthroplasty.

BACKGROUND: Up to 25% of patients requiring hip or knee arthroplasty have sleep apnea (SA), and these patients have historically been excluded from outpatient programs. The objectives of this study were to evaluate same-day discharge failure as well as 30-day complications, readmissions, and unexpected visits. METHODS: A retrospective case-control study comparing patients who have and do not have SA matched for age, sex and arthroplasty type (total hip arthroplasty, total knee arthroplasty, unicompartimental knee arthroplasty) who underwent primary outpatient surgery between February 2019 and December 2022 in 2 academic hospitals was conducted. Cases with mild SA, moderate SA with a body mass index (BMI) <35, and SA of all severity treated by continuous positive airway pressure machines were eligible. There were 156 patients included (78 cases). Complications were assessed according to the Clavien-Dindo Classification and the Comprehensive Complication Index. Continuous variables were evaluated by Student's T or Mann-Whitney tests, while categorical data were analyzed by Chi-square or Fisher tests. Univariate analyses were performed to determine discharge failure risk factors. RESULTS: There were 6 cases (7.7%) and 5 controls (6.4%) who failed to be discharged on surgery day (P = .754), with postoperative hypoxemia (6, [3.8%]) and apnea periods (3, [1.9%]) being the most common causes. Higher BMI (odds ratio = 1.19, P = .013) and general anesthesia (odds ratio = 11.97, P = .004) were found to be risk factors for discharge failure. No difference was observed on 30-day readmissions (P = .497), unexpected visits (P = 1.000), and complications on the Clavien-Dindo Classification (P > .269) and Comprehensive Complication Index (P > .334) scales. CONCLUSIONS: Selected patients who have SA can safely undergo outpatient hip or knee arthroplasty. Higher BMI and general anesthesia increased the odds of same-day discharge failure. LEVEL OF EVIDENCE: Level III, Case-control Study.

Transcriptomic Analysis of Mineralized Adipose-Derived Stem Cell Tissues for Calcific Valve Disease Modelling.

Calcific aortic valve disease (CAVD) is characterized by the fibrosis and mineralization of the aortic valve, which leads to aortic stenosis and heart failure. At the cellular level, this is due to the osteoblastic-like differentiation of valve interstitial cells (VICs), resulting in the calcification of the tissue. Unfortunately, human VICs are not readily available to study CAVD pathogenesis and the implicated mechanisms in vitro; however, adipose-derived stromal/stem cells (ASCs), carrying the patient's specific genomic features, have emerged as a promising cell source to model cardiovascular diseases due to their multipotent nature, availability, and patient-specific characteristics. In this study, we describe a comprehensive transcriptomic analysis of tissue-engineered, scaffold-free, ASC-embedded mineralized tissue sheets using bulk RNA sequencing. Bioinformatic and gene set enrichment analyses revealed the up-regulation of genes associated with the organization of the extracellular matrix (ECM), suggesting that the ECM could play a vital role in the enhanced mineralization observed in these tissue-engineered ASC-embedded sheets. Upon comparison with publicly available gene expression datasets from CAVD patients, striking similarities emerged regarding cardiovascular diseases and ECM functions, suggesting a potential link between ECM gene expression and CAVDs pathogenesis. A matrisome-related sub-analysis revealed the ECM microenvironment promotes the transcriptional activation of the master gene runt-related transcription factor 2 (RUNX2), which is essential in CAVD development. Tissue-engineered ASC-embedded sheets with enhanced mineralization could be a valuable tool for research and a promising avenue for the identification of more effective aortic valve replacement therapies.

Drivers of employment dynamics of AI innovators.

Based on an analysis of companies developing artificial intelligence (AI) technologies, this study offers fresh evidence on the role of innovation as one of the drivers of employment growth. GMM-SYS estimates on a worldwide longitudinal dataset covering 4,184 firms that patented inventions involving AI technologies between 2000 and 2016 show a positive and significant impact of AI patent families on employment. The effect, presumably of product innovations, is small in magnitude and limited to service sectors and younger firms, which are at the forefront of the leaders of the AI revolution. We also detect some evidence of increasing returns, suggesting that innovative companies more focused on AI technologies are achieving larger impacts in terms of job creation.

Heterozygous NF1 dermal fibroblasts modulate exosomal content to promote angiogenesis in a tissue-engineered skin model of neurofibromatosis type-1.

Neovascularization is a critical process in tumor progression and malignant transformation associated with neurofibromatosis type 1 (NF1). Indeed, fibroblasts are known to play a key role in the tumoral microenvironment modification by producing an abundant collagenous matrix, but their contribution in paracrine communication pathways is poorly understood. Here, we hypothesized that NF1 heterozygosis in human dermal fibroblasts could promote angiogenesis through exosomes secretion. The purposes of this study are to identify the NF1 fibroblast-derived exosome protein contents and to determine their proangiogenic activity. Angiogenic proteome measurement confirmed the overexpression of VEGF and other proteins involved in vascularization. Tube formation of microvascular endothelial cells was also enhanced in presence of exosomes derived from NF1 skin fibroblasts. NF1 tissue-engineered skin (NF1-TES) generation showed a significantly denser microvessels networks compared to healthy controls. The reduction of exosomes production with an inhibitor treatment demonstrated a drastic decrease in blood vessel formation within the dermis. Our results suggest that NF1 haploinsufficiency alters the dermal fibroblast function and creates a pro-angiogenic signal via exosomes, which increases the capillary formation. This study highlights the potential of targeting exosome secretion and angiogenesis for therapeutic interventions in NF1.

Grip selection without tool knowledge: end-state comfort effect in familiar and novel tool use.

A well-known phenomenon for the study of movement planning is the end-state comfort (ESC) effect: When they reach and grasp tools, individuals tend to adopt uncomfortable initial hand postures if that allows a subsequent comfortable final posture. In the context of tool use, this effect is modulated by tool orientation, task goal, and cooperation. However, the cognitive bases of the ESC effect remain unclear. The goal of this study was to determine the contribution of semantic tool knowledge and technical reasoning to movement planning, by testing whether the ESC effect typically observed with familiar tools would also be observed with novel tools. Twenty-six participants were asked to reach and grasp familiar and novel tools under varying conditions (i.e., tool's handle downward vs. upward; tool transport vs. use; solo vs. cooperation). In our findings, the effects of tool orientation, task goal and cooperation were replicated with novel tools. It follows that semantic tool knowledge is not critical for the ESC effect to occur. In fact, we found an "habitual" effect: Participant adopted uncomfortable grips with familiar tools even when it was not necessary (i.e., to transport them), probably because of the interference of habitual movement programming with actual movement programming. A cognitive view of movement planning is proposed, according to which goal comprehension (1) may rely on semantic tool knowledge, technical reasoning, and/or social skills, (2) defines end-state configuration, which in turn (3) calibrates beginning-state comfort and hence the occurrence of the ESC effect.

A fist bump in a political meeting? The influence of social context on affordance selection.

Historically, understanding human cognition such as action processing has been a challenging issue in cognitive neuropsychology and the more we know about cognition, the more we shape it as a complex, multi-determined phenomenon that is embedded in a social context. The present study aimed at understanding how the social context could influence affordance selection. We hypothesized that affordance selection would be modulated by social context and that a given hand configuration would be considered appropriate or not, as a function of the presence or absence of social context. Twenty-six healthy participants were asked to judge the appropriateness of three variants of 10 hand-object interactions based on photographs presented with or without a visual, social context. In our results, hand configurations were intrinsically acceptable or not, but this effect was modulated by the social context. A three-step model of the influence of social context on affordance selection was proposed, according to which selection depends on social norms, in the form of social knowledge and social context analysis.

Antibiotics and Antibiotic Resistance-Mur Ligases as an Antibacterial Target.

The emergence of Multidrug Resistance (MDR) strains of bacteria has accelerated the search for new antibacterials. The specific bacterial peptidoglycan biosynthetic pathway represents opportunities for the development of novel antibacterial agents. Among the enzymes involved, Mur ligases, described herein, and especially the amide ligases MurC-F are key targets for the discovery of multi-inhibitors, as they share common active sites and structural features.

Moyamoya Disease Susceptibility Gene RNF213 Regulates Endothelial Barrier Function.

BACKGROUND: Variants in the ring finger protein 213 (RNF213) gene are known to be associated with increased predisposition to cerebrovascular diseases development. Genomic studies have identified RNF213 as a major risk factor of Moyamoya disease in East Asian descendants. However, little is known about the RNF213 (ring finger protein 213) biological functions or its associated pathogenic mechanisms underlying Moyamoya disease. METHODS: To investigate RNF213 loss-of-function effect in endothelial cell, stable RNF213-deficient human cerebral endothelial cells were generated using the CRISPR-Cas9 genome editing technology. RESULTS: In vitro assays, using RNF213 knockout brain endothelial cells, showed clear morphological changes and increased blood-brain barrier permeability. Downregulation and delocalization of essential interendothelial junction proteins involved in the blood-brain barrier maintenance, such as PECAM-1 (platelet endothelial cell adhesion molecule-1), was also observed. Brain endothelial RNF213-deficient cells also showed an abnormal potential to transmigration of leukocytes and secreted high amounts of proinflammatory cytokines. CONCLUSIONS: Taken together, these results indicate that RNF213 could be a key regulator of cerebral endothelium integrity, whose disruption could be an early pathological mechanism leading to Moyamoya disease. This study also further reinforces the importance of blood-brain barrier integrity in the development of Moyamoya disease and other RNF213-associated diseases.

Chemical Approaches to Carbocyclic Nucleosides.

Nucleoside analogues are at the forefront of antiviral therapy for last decades. To circumvent some of their limitations, based on their metabolism, and in order to improve their anti-viral potency and selectivity, several families of nucleoside analogues have been described through structural modifications at the sugar and heterocycles. The replacement of the oxygen of the nucleoside by a methylene has led to the family of carbocyclic (or cyclopentane) nucleoside analogues. Various potent anti-HIV and anti-HBV drugs belong to this family. Main syntheses of carbocyclic analogues of nucleosides used Diels-Alder reactions (in racemic or asymmetric series), but also started from carbohydrates (ribose, glucose), as a source of optically active compounds, which then had to be transformed into carbacycles under various conditions. The growing interest in carbocyclic nucleosides has led several groups, including ours, to develop new analogues and to explore novel routes. This article will review some of the recent chemistry developed on selected five-membered ring carbocyclic nucleosides.

Tunable Approach to C-Linked Analogs of Glycosamines.

The synthesis of (1R)-2-amino-2-deoxy-ß-l-gulopyranosyl benzene and the α and ß forms of 2-amino-2-deoxy-l-idopyranosyl benzene derivatives was accomplished through stereospecific addition of tributylstannyllithium to readily available (SR)- or (SS)-N-tert-butanesulfinyl-arabinofuranosylamine building blocks, followed by stereoretentive Pd-catalyzed Migita-Kosugi-Stille cross-coupling, stereoselective reduction, and an activation-cyclization strategy. Application of this methodology paves the way to new three-dimensional chemical space and preparation of unknown (non-natural) and complex 2-amino-2-deoxy sugars of biological interest.

Impact of Exosomes Released by Different Corneal Cell Types on the Wound Healing Properties of Human Corneal Epithelial Cells.

Corneal wound healing involves communication between the different cell types that constitute the three cellular layers of the cornea (epithelium, stroma and endothelium), a process ensured in part by a category of extracellular vesicles called exosomes. In the present study, we isolated exosomes released by primary cultured human corneal epithelial cells (hCECs), corneal fibroblasts (hCFs) and corneal endothelial cells (hCEnCs) and determined whether they have wound healing characteristics of their own and to which point they modify the genetic and proteomic pattern of these cell types. Exosomes released by all three cell types significantly accelerated wound closure of scratch-wounded hCECs in vitro compared to controls (without exosomes). Profiling of activated kinases revealed that exosomes from human corneal cells caused the activation of signal transduction mediators that belong to the HSP27, STAT, ß-catenin, GSK-3ß and p38 pathways. Most of all, data from gene profiling analyses indicated that exosomes, irrespective of their cellular origin, alter a restricted subset of genes that are completely different between each targeted cell type (hCECs, hCFS, hCEnCs). Analysis of the genes specifically differentially regulated for a given cell-type in the microarray data using the Ingenuity Pathway Analysis (IPA) software revealed that the mean gene expression profile of hCECs cultured in the presence of exosomes would likely promote cell proliferation and migration whereas it would reduce differentiation when compared to control cells. Collectively, our findings represent a conceptual advance in understanding the mechanisms of corneal wound repair that may ultimately open new avenues for the development of novel therapeutic approaches to improve closure of corneal wounds.

Synthesis and Structure-Activity Relationship Studies of Pyrido [1,2-e]Purine-2,4(1H,3H)-Dione Derivatives Targeting Flavin-Dependent Thymidylate Synthase in Mycobacterium tuberculosis.

In 2002, a new class of thymidylate synthase (TS) involved in the de novo synthesis of dTMP named Flavin-Dependent Thymidylate Synthase (FDTS) encoded by the thyX gene was discovered; FDTS is present only in 30% of prokaryote pathogens and not in human pathogens, which makes it an attractive target for the development of new antibacterial agents, especially against multi-resistant pathogens. We report herein the synthesis and structure-activity relationship of a novel series of hitherto unknown pyrido[1,2-e]purine-2,4(1H,3H)-dione analogues. Several synthetics efforts were done to optimize regioselective N1-alkylation through organopalladium cross-coupling. Modelling of potential hits were performed to generate a model of interaction into the active pocket of FDTS to understand and guide further synthetic modification. All those compounds were evaluated on an in-house in vitro NADPH oxidase assays screening as well as against Mycobacterium tuberculosis ThyX. The highest inhibition was obtained for compound 23a with 84.3% at 200 µM without significant cytotoxicity (CC50 > 100 µM) on PBM cells.

Synthesis of acyclic nucleoside phosphonates targeting flavin-dependent thymidylate synthase in Mycobacterium tuberculosis.

Flavin-Dependent Thymidylate Synthase (FDTS) encoded by ThyX gene was discovered as a new class of thymidylate synthase involved in the de novo synthesis of dTMP named only in 30 % of human pathogenic bacteria. This target was pursed for the development of new antibacterial agents against multiresistant pathogens. We have developed a new class of ANPs based on the mimic of two natural's cofactors (dUMP and FAD) as inhibitors against Mycobacterium tuberculosis ThyX. Several synthetic efforts were performed to optimize regioselective N1-alkylation, cross-coupling metathesis and Sonogashira cross-coupling. Compound 19c showed a poor 31.8% inhibitory effect on ThyX at 200 µM.

Synthesis and Antiviral Evaluation of (1,4-Disubstituted-1,2,3-Triazol)-(E)-2-Methyl-but-2-Enyl Nucleoside Phosphonate Prodrugs.

A series of hitherto unknown (1,4-disubstituted-1,2,3-triazol)-(E)-2-methyl-but-2-enyl nucleosides phosphonate prodrugs bearing 4-substituted-1,2,3-triazoles were prepared in a straight approach through an olefin acyclic cross metathesis as the key synthetic step. All novel compounds were evaluated for their antiviral activities against HBV, HIV and SARS-CoV-2. Among these molecules, only compound 15j, a hexadecyloxypropyl (HDP)/(isopropyloxycarbonyl-oxymethyl)-ester (POC) prodrug, showed activity against HBV in Huh7 cell cultures with 62% inhibition at 10 µM, without significant cytotoxicity (IC50 = 66.4 µM in HepG2 cells, IC50 = 43.1 µM in HepG2 cells) at 10 µM.

Thiopurine Derivative-Induced Fpg/Nei DNA Glycosylase Inhibition: Structural, Dynamic and Functional Insights.

DNA glycosylases are emerging as relevant pharmacological targets in inflammation, cancer and neurodegenerative diseases. Consequently, the search for inhibitors of these enzymes has become a very active research field. As a continuation of previous work that showed that 2-thioxanthine (2TX) is an irreversible inhibitor of zinc finger (ZnF)-containing Fpg/Nei DNA glycosylases, we designed and synthesized a mini-library of 2TX-derivatives (TXn) and evaluated their ability to inhibit Fpg/Nei enzymes. Among forty compounds, four TXn were better inhibitors than 2TX for Fpg. Unexpectedly, but very interestingly, two dithiolated derivatives more selectively and efficiently inhibit the zincless finger (ZnLF)-containing enzymes (human and mimivirus Neil1 DNA glycosylases hNeil1 and MvNei1, respectively). By combining chemistry, biochemistry, mass spectrometry, blind and flexible docking and X-ray structure analysis, we localized new TXn binding sites on Fpg/Nei enzymes. This endeavor allowed us to decipher at the atomic level the mode of action for the best TXn inhibitors on the ZnF-containing enzymes. We discovered an original inhibition mechanism for the ZnLF-containing Fpg/Nei DNA glycosylases by disulfide cyclic trimeric forms of dithiopurines. This work paves the way for the design and synthesis of a new structural class of inhibitors for selective pharmacological targeting of hNeil1 in cancer and neurodegenerative diseases.

Design and Synthesis of Various 5'-Deoxy-5'-(4-Substituted-1,2,3-Triazol-1-yl)-Uridine Analogues as Inhibitors of Mycobacterium tuberculosis Mur Ligases.

The synthesis of hitherto unknown 5'-deoxy-5'-(4-substituted-1,2,3-triazol-1-yl)-uridine and its evaluation, through an one-pot screening assay, against MurA-F enzymes involved in Mycobacterium tuberculosis (Mtb), are described. Starting from UDP-N-acetylmuramic acid (UDP-MurNAc), the natural substrate involved in the peptidoglycan biosynthesis, our strategy was to substitute the diphosphate group of UDP-MurNAc by a 1,2,3-triazolo spacer under copper-catalyzed azide-alkyne cycloaddition conditions. The structure-activity relationship was discussed and among the 23 novel compounds developed, N-acetylglucosamine analogues 11c and 11e emerged as the best inhibitors against the Mtb MurA-F enzymes reconstruction pathway with an inhibitory effect of 56% and 50%, respectively, at 100 µM. Both compounds are selective inhibitors of Mtb MurE, the molecular docking and molecular dynamic simulation suggesting that 11c and 11e are occupying the active site of Mtb MurE ligase.

Presence of three mutations in the fumarylacetoacetate hydrolase gene in a patient with atypical symptoms of hereditary tyrosinemia type I.

Hereditary tyrosinemia type 1 (HT1), the most severe disease of the tyrosine catabolic pathway, is caused by a deficiency of fumarylacetoacetate hydrolase (FAH). More than 90 disease-causing variants have been identified in the fah gene. We investigated the molecular defect in a patient who presented atypical symptoms for the disease. No immunoreactive FAH was found in the liver and RNA analysis by RT-PCR suggested the presence of splicing mutations. Indeed, the patient was revealed to be a compound heterozygote for IVS6-1 g- > t and two new variants, namely p.V259L and p.G398E. Using splicing minigene constructs transfected in HeLa cells, the c.775G > C variant (p.V259L) was shown to affect partially exon 9 splicing thereby allowing the production of some full-length double-mutant FAH transcripts. The p.G398E variant had a major impact on enzyme activity, which was worsened by the p.V259L variant. Surprisingly, the double mutant protein was expressed to similar level as the wild-type protein upon transfection in HeLa cells but was absent in the patient liver extract, suggesting a higher propensity to be degraded in the hepatocellular context.