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48 result(s) for "de Murat, Daniel"
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Impact of steroid differentiation on tumor microenvironment revealed by single-nucleus atlas of adrenal tumors
Adrenocortical carcinomas (ACC) are aggressive and resistant to medical treatment. This study reports a single-nucleus transcriptome atlas of steroid and microenvironment cells in 38 human normal adrenals and adrenocortical tumors. We identify intermediate-state cells between glomerulosa and fasciculata, a transition state in the centripetal trans-differentiation of normal steroid cells. In tumors, steroid cells show expression programs reflecting this zonation. Although ACC microenvironment is scarce, its signatures combine with those of steroid cells into ecotypes. A first ecotype combines cancer-associated fibroblasts, tumor-associated endothelial cells, with hypoxia and mitosis signatures in steroid cells. Another ecotype combines exhausted T cells, with fasciculata steroid signature. These ecotypes are associated with poor survival. Conversely, a third ecotype combines inflammatory macrophages, with reticularis steroid signature, and better outcome. These steroid/microenvironment cells interplays improve outcome predictions and may open therapeutic options in aggressive ACC, through immune microenvironment activation by modulating glucocorticoids/androgens balance. Adrenocortical carcinomas (ACC) are aggressive and often resistant to therapy. Here, the authors provide a single-nucleus transcriptomic atlas of ACCs and normal adrenal glands, finding ecotypes in steroid and microenvironment cells that are associated with clinical outcomes.
Somatic Molecular Heterogeneity in Bilateral Macronodular Adrenocortical Disease (BMAD) Differs Among the Pathological Subgroups
Bilateral macronodular adrenocortical disease (BMAD) is an uncommon cause of Cushing’s syndrome leading to bilateral macronodules. Isolated BMAD has been classified into three molecular groups: patients with ARMC5 alteration, KDM1A alteration, and patients without known genetic cause. The aim of this study was to identify by NGS, in a cohort of 26 patients with BMAD, the somatic alterations acquired in different nodules after macrodissection from patients with germline ARMC5 or KDM1A alterations and to analyze potential somatic alterations in a panel of five other genes involved in adrenal pathology (GNAS, PDE8B, PDE11A, PRKAR1A, and PRKACA). Twenty-three patients (7 ARMC5, 3 KDM1A, and 13 BMAD with unknown genetic cause) were analyzable. Somatic ARMC5 or KDM1A events were exclusively observed in patients with germline ARMC5 and KDM1A alterations, respectively. Six out of 7 ARMC5 patients have a high heterogeneity in identified somatic events, whereas one ARMC5 and all KDM1A patients show a loss of heterozygosity (LOH) in all nodules. Except for passenger alterations of GNAS, no genetic alteration susceptible to causing the disease was detected in the BMAD with unknown genetic cause. Our study reinforces our knowledge of the somatic genetic heterogeneity of ARMC5 and the somatic homogeneity of KDM1A. It reveals the absence of purely somatic events in these two genes and provides a new tool for detecting KDM1A alterations by FISH 1p36/1q25.
Whole blood transcriptome signature predicts severe forms of COVID-19: Results from the COVIDeF cohort study
COVID-19 is associated with heterogeneous outcome. Early identification of a severe progression of the disease is essential to properly manage the patients and improve their outcome. Biomarkers reflecting an increased inflammatory response, as well as individual features including advanced age, male gender, and pre-existing comorbidities, are risk factors of severe COVID-19. Yet, these features show limited accuracy for outcome prediction. The aim was to evaluate the prognostic value of whole blood transcriptome at an early stage of the disease. Blood transcriptome of patients with mild pneumonia was profiled. Patients with subsequent severe COVID-19 were compared to those with favourable outcome, and a molecular predictor based on gene expression was built. Unsupervised classification discriminated patients who would later develop a COVID-19-related severe pneumonia. The corresponding gene expression signature reflected the immune response to the viral infection dominated by a prominent type I interferon, with IFI27 among the most over-expressed genes. A 48-genes transcriptome signature predicting the risk of severe COVID-19 was built on a training cohort, then validated on an external independent cohort, showing an accuracy of 81% for predicting severe outcome. These results identify an early transcriptome signature of severe COVID-19 pneumonia, with a possible relevance to improve COVID-19 patient management.
224 Epigenetic and signaling-based engineering enhances CAR-T cell function in primary central nervous system lymphoma
BackgroundPrimary central nervous system lymphoma (PCNSL) is an aggressive B-cell malignancy confined to the CNS (brain, cerebrospinal fluid, spinal cord, and/or eye), with limited treatment options upon relapse. While CD19-directed CAR-T cell therapies have revolutionized the treatment of systemic B-cell malignancies, their application in PCNSL has been limited by neurotoxicity concerns. Recent studies have demonstrated safety and feasibility; however, relapse remains common, underscoring the need for more durable and CNS-adapted CAR-T cell products.MethodsWe evaluated a panel of second-generation CD19 CAR constructs, including ITAM-tuned ‘1XX’ variants, using a 3D spheroid model of PCNSL. The (SJ25C1)1XX-CAR format showed superior antitumor activity. To enhance CAR-T cell persistence and reduce exhaustion, we used CRISPR/Cas9 to knockout SUV39H1, a histone methyltransferase that regulates H3K9 trimethylation and limits memory T cell differentiation. CAR-T cells expressing the (SJ25C1)1XX-CAR and lacking SUV39H1 were evaluated in vitro and in vivo.ResultsSUV39H1-deficient (SJ25C1)1XX CAR-T cells showed increased expression of memory-associated genes and reduced expression of dysfunction and exhaustion markers in vitro. In an orthotopic PCNSL xenograft model, these dual-engineered T cells achieved superior tumor control and extended survival compared to conventional second-generation CAR-T cells. When compared to non-edited (SJ25C1)1XX-CAR-T cells, survival outcomes were similar, likely reflecting the high baseline efficacy and absence of relapse in this model. Nevertheless, ex vivo single-cell RNA sequencing and spectral flow cytometry confirmed that SUV39H1 knockout enhanced memory features and reduced exhaustion signatures. To assess long-term functional persistence, we developed a vitreoretinal lymphoma rechallenge model that allows delayed tumor re-exposure following initial remission.ConclusionsThese data support the clinical translation of a next-generation cell therapy for PCNSL based on epigenetically reprogrammed, signaling-optimized CAR-T cells. We are currently developing a GMP-compatible process incorporating the RQR8 marker/suicide switch for enrichment and rituximab-mediated elimination in the event of unexpected toxicity, in preparation for a future phase I/II clinical trial.
Somatotroph Tumors and the Epigenetic Status of the GNAS Locus
Forty percent of somatotroph tumors harbor recurrent activating GNAS mutations, historically called the gsp oncogene. In gsp-negative somatotroph tumors, GNAS expression itself is highly variable; those with GNAS overexpression most resemble phenotypically those carrying the gsp oncogene. GNAS is monoallelically expressed in the normal pituitary due to methylation-based imprinting. We hypothesize that changes in GNAS imprinting of gsp-negative tumors affect GNAS expression levels and tumorigenesis. We characterized the GNAS locus in two independent somatotroph tumor cohorts: one of 23 tumors previously published (PMID: 31883967) and classified by pan-genomic analysis, and a second with 82 tumors. Multi-omics analysis of the first cohort identified a significant difference between gsp-negative and gsp-positive tumors in the methylation index at the known differentially methylated region (DMR) of the GNAS A/B transcript promoter, which was confirmed in the larger series of 82 tumors. GNAS allelic expression was analyzed using a polymorphic Fok1 cleavage site in 32 heterozygous gsp-negative tumors. GNAS expression was significantly reduced in the 14 tumors with relaxed GNAS imprinting and biallelic expression, compared to 18 tumors with monoallelic expression. Tumors with relaxed GNAS imprinting showed significantly lower SSTR2 and AIP expression levels. Altered A/B DMR methylation was found exclusively in gsp-negative somatotroph tumors. 43% of gsp-negative tumors showed GNAS imprinting relaxation, which correlated with lower GNAS, SSTR2 and AIP expression, indicating lower sensitivity to somatostatin analogues and potentially aggressive behavior.
Safety and clinical activity of autologous RNA chimeric antigen receptor T-cell therapy in myasthenia gravis (MG-001): a prospective, multicentre, open-label, non-randomised phase 1b/2a study
Chimeric antigen receptor (CAR) T cells are highly effective in treating haematological malignancies, but associated toxicities and the need for lymphodepletion limit their use in people with autoimmune disease. To explore the use of CAR T cells for the treatment of people with autoimmune disease, and to improve their safety, we engineered them with RNA (rCAR-T)—rather than the conventional DNA approach—to target B-cell maturation antigen (BCMA) expressed on plasma cells. To test the suitability of our approach, we used rCAR-T to treat individuals with myasthenia gravis, a prototypical autoantibody disease mediated partly by pathogenic plasma cells. MG-001 was a prospective, multicentre, open-label, phase 1b/2a study of Descartes-08, an autologous anti-BCMA rCAR-T therapy, in adults (ie, aged ≥18 years) with generalised myasthenia gravis and a Myasthenia Gravis Activities of Daily Living (MG-ADL) score of 6 or higher. The study was done at eight sites (ie, academic medical centres or community neurology clinics) in the USA. Lymphodepletion chemotherapy was not used. In part 1 (phase 1b), participants with Myasthenia Gravis Foundation of America (MGFA) disease class III–IV generalised myasthenia gravis received three ascending doses of Descartes-08 to determine a maximum tolerated dose. In part 2 (phase 2a), participants with generalised myasthenia gravis with MGFA disease class II–IV received six doses at the maximum tolerated dose in an outpatient setting. The primary objective was to establish safety and tolerability of Descartes-08; secondary objectives were to assess myasthenia gravis disease severity and biomarkers in participants who received Descartes-08. This trial is registered with clinicaltrials.gov, NCT04146051. We recruited 16 individuals for screening between Jan 7, 2020 and Aug 3, 2022. 14 participants were enrolled (n=3 in part 1, n=11 in part 2). Ten participants were women and four were men. Two individuals did not qualify due to low baseline MG-ADL score (n=1) or lack of generalised disease (n=1). Median follow-up in part 2 was 5 months (range 3–9 months). There was no dose-limiting toxicity, cytokine release syndrome, or neurotoxicity. Common adverse events were headache (six of 14 participants), nausea (five of 14), vomiting (three of 14), and fever (four of 14), which resolved within 24 h of infusion. Fevers were not associated with increased markers of cytokine release syndrome (IL-6, IL-2, and TNF). Mean improvements from baseline to week 12 were –6 (95% CI –9 to –3) for MG-ADL score, –7 (–11 to –3) for Quantitative Myasthenia Gravis score, –14 (–19 to –9) for Myasthenia Gravis Composite score, and –9 (–15 to –3) for Myasthenia Gravis Quality of Life 15-revised score. In this first study of an rCAR-T therapy in individuals with an autoimmune disease, Descartes-08 appeared to be safe and was well tolerated. Descartes-08 infusions were followed by clinically meaningful decreases on myasthenia gravis severity scales at up to 9 months of follow-up. rCAR-T therapy warrants further investigation as a potential new treatment approach for individuals with myasthenia gravis and other autoimmune diseases. Cartesian Therapeutics and National Institute of Neurological Disorders and Stroke of the National Institutes of Health.
Exome sequencing implicates genetic disruption of prenatal neuro-gliogenesis in sporadic congenital hydrocephalus
Congenital hydrocephalus (CH), characterized by enlarged brain ventricles, is considered a disease of excessive cerebrospinal fluid (CSF) accumulation and thereby treated with neurosurgical CSF diversion with high morbidity and failure rates. The poor neurodevelopmental outcomes and persistence of ventriculomegaly in some post-surgical patients highlight our limited knowledge of disease mechanisms. Through whole-exome sequencing of 381 patients (232 trios) with sporadic, neurosurgically treated CH, we found that damaging de novo mutations account for >17% of cases, with five different genes exhibiting a significant de novo mutation burden. In all, rare, damaging mutations with large effect contributed to ~22% of sporadic CH cases. Multiple CH genes are key regulators of neural stem cell biology and converge in human transcriptional networks and cell types pertinent for fetal neuro-gliogenesis. These data implicate genetic disruption of early brain development, not impaired CSF dynamics, as the primary pathomechanism of a significant number of patients with sporadic CH. The largest whole-exome sequencing study of sporadic congenital hydrocephalus identities mutations associated with disrupted fetal neuro-gliogenesis as the primary pathophysiological event in a significant number of cases.
Modifiable determinants of older adults’ physical activity and sedentary behavior in community and healthcare settings: a DE-PASS systematic review and meta-analysis
Objectives To identify the modifiable determinants targeted in interventions involving older adults, and to determine which of these interventions effectively increased physical activity (PA) and/or reduced sedentary behaviour (SB). Additionally, to explore whether the effects of these interventions vary based on the implementation setting. Methods A search of randomized controlled trials (RCTs) and controlled trials (CTs) was performed in Medline, APA PsycArticles, SPORTDiscus, and Web of Science. Risk of bias assessment was performed with Cochrane’s tool. Modifiable determinants were narratively synthesized, and random-effects models were performed to meta-analyse studies reporting device-measured physical activity or sedentary behaviour. Moderator analyses were performed to investigate the role of implementation setting. Standardized between-group mean difference (SMD) with 95% confidence interval (CI) was used to indicate effect sizes. Results From 31,727 individual records, 52 eligible studies published between 2012–2022 were identified, 30 and 22 studies from community and health care settings, respectively. Determinants within the category physical health and wellbeing ( n  = 23) were most frequently reported while only one study reported determinants within a social or cultural context. Eighteen studies were included in the meta-analysis. Interventions targeting physical health and wellbeing revealed an increase in steps (SMD = 0.46; 95%CI: 0.15 to 0.77) and minutes of moderate-to-vigorous intensity physical activity (SMD = 0.41; 95%CI: 0.19 to 0.64) among intervention participants compared to controls, whereas interventions targeting psychological or behavioural determinants showed no between-group differences in steps (SMD = 0.10; 95%CI: -0.12 to 0.32) and moderate-to-vigorous intensity physical activity (SMD = 0.26; 95%CI: -0.24 to -0.75). Interventions targeting physical health and wellbeing showed significant heterogeneity ( p  < 0.0001; I 2  = 73.10%). Subgroup analyses showed a significant effect on device-measured physical activity for the eight community-based interventions (SMD = 0.42; 95%CI: 0.07 to 0.77), while no significant effect was found for the eight studies performed in healthcare settings (SMD = 0.26; 95%CI; -0.10 to 0.62). Conclusion Interventions targeting physical health and wellbeing may increase PA in older adults, with community-based studies appearing more effective than studies in healthcare settings. The significant heterogeneity of study findings indicates that further research is needed to fully understand the influence of PA and SB determinants across settings, particularly those related to psychological, behavioural, social, and cultural factors. Systematic review registration PROSPERO: CRD42022287606.
Super-resolution imaging of synaptic and Extra-synaptic AMPA receptors with different-sized fluorescent probes
Previous studies tracking AMPA receptor (AMPAR) diffusion at synapses observed a large mobile extrasynaptic AMPAR pool. Using super-resolution microscopy, we examined how fluorophore size and photostability affected AMPAR trafficking outside of, and within, post-synaptic densities (PSDs) from rats. Organic fluorescent dyes (≈4 nm), quantum dots, either small (≈10 nm diameter; sQDs) or big (>20 nm; bQDs), were coupled to AMPARs via different-sized linkers. We find that >90% of AMPARs labeled with fluorescent dyes or sQDs were diffusing in confined nanodomains in PSDs, which were stable for 15 min or longer. Less than 10% of sQD-AMPARs were extrasynaptic and highly mobile. In contrast, 5–10% of bQD-AMPARs were in PSDs and 90–95% were extrasynaptic as previously observed. Contrary to the hypothesis that AMPAR entry is limited by the occupancy of open PSD ‘slots’, our findings suggest that AMPARs rapidly enter stable ‘nanodomains’ in PSDs with lifetime >15 min, and do not accumulate in extrasynaptic membranes. Forgetting is a common experience in our everyday life. Yet much remains unknown about how we remember, and about why our memories sometimes fail us. The brain contains 80 to 100 billion nerve cells or neurons, which communicate with one another at junctions called synapses. At a synapse, one neuron releases a chemical message, which must diffuse across a small gap, and then activate proteins called receptors on another neuron. If the first neuron activates the second repeatedly, the second cell responds by inserting additional receptors into its membrane at the synapse. This strengthens the connection between the two neurons. Strengthening of synapses is thought to be one of the key mechanisms underlying learning. To confirm this, it would be helpful to be able to monitor the movement and position of individual receptors at synapses. However, the space between the two nerve cells at at synapse, called the synaptic cleft, is no more than 40 nanometers wide. This is about 25 times thinner than a human hair, and too small to be seen with light microscopy. Electron microscopy can visualize synapses, but does not work in living tissue. The only other option is to attach a fluorescent label – either a dye or a man-made crystal called a quantum dot – to a protein found in synapses and monitor the resulting fluorescence. Though the probe must be small enough to pass through the synaptic cleft to do this. Using fluorescence microscopy, researchers have examined the distribution in synapses of proteins called AMPA receptors, which have a key role in memory. Multiple studies have shown groups of AMPA receptors gathered outside synapses. This has led to the suggestion that during learning, AMPA receptors wait outside the synapse until a space becomes available within the synapse’s membrane. However, this has yet to be confirmed directly, in part because conventional fluorescent dyes and quantum dots are too bulky to enter synaptic clefts when bound to a receptor. Lee et al. have now developed a quantum dot that is only 10 nanometers wide and therefore small enough to enter the synaptic cleft with an AMPA receptor attached. These small quantum dots were then used to label AMPA receptors in neurons collected from rats and then grown in a petri dish, which provided a completely new view of synapses. The images show that the majority of AMPA receptors in neurons circulate within confined domains – a little like holding pens – inside the synapse, rather than waiting outside as previously assumed. Labeling the receptors with smaller 4-nanometer-wide fluorescent tags produces a similar picture. Further work is still need to determine how AMPA receptors get into the synapse and contribute to new memories.
Incident type 2 diabetes attributable to suboptimal diet in 184 countries
The global burden of diet-attributable type 2 diabetes (T2D) is not well established. This risk assessment model estimated T2D incidence among adults attributable to direct and body weight-mediated effects of 11 dietary factors in 184 countries in 1990 and 2018. In 2018, suboptimal intake of these dietary factors was estimated to be attributable to 14.1 million (95% uncertainty interval (UI), 13.8–14.4 million) incident T2D cases, representing 70.3% (68.8–71.8%) of new cases globally. Largest T2D burdens were attributable to insufficient whole-grain intake (26.1% (25.0–27.1%)), excess refined rice and wheat intake (24.6% (22.3–27.2%)) and excess processed meat intake (20.3% (18.3–23.5%)). Across regions, highest proportional burdens were in central and eastern Europe and central Asia (85.6% (83.4–87.7%)) and Latin America and the Caribbean (81.8% (80.1–83.4%)); and lowest proportional burdens were in South Asia (55.4% (52.1–60.7%)). Proportions of diet-attributable T2D were generally larger in men than in women and were inversely correlated with age. Diet-attributable T2D was generally larger among urban versus rural residents and higher versus lower educated individuals, except in high-income countries, central and eastern Europe and central Asia, where burdens were larger in rural residents and in lower educated individuals. Compared with 1990, global diet-attributable T2D increased by 2.6 absolute percentage points (8.6 million more cases) in 2018, with variation in these trends by world region and dietary factor. These findings inform nutritional priorities and clinical and public health planning to improve dietary quality and reduce T2D globally. Modeling analysis from the Global Dietary Database estimated that 70% of new global cases of type 2 diabetes are attributable to suboptimal intake of 11 dietary factors, with substantial differences in dietary risks across world regions and nations.