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Enteroendocrine cells (EECs) are rare intestinal epithelial cells producing multiple hormones that regulate essential aspects of digestion and energy. EEC subtypes, their hormone repertoire and differentiation mechanisms from intestinal stem cells have been characterized in the adult intestine. Although EECs must be functional from birth because their absence leads to severe intestinal malabsorption in newborns, the processes that determine their subtype specification during development remain largely unknown. We used mouse embryos, human pluripotent stem cell-derived intestinal organoid models and single-cell transcriptomics to characterize EEC lineages and dynamics during development. Our findings demonstrate that in both mice and humans, the majority of EECs are specified during development through similar differentiation trajectories to those observed in the adult intestine. This suggests that EEC subtype specification occurs independently of fully organized crypt-villus structures and stimulation by diet or microbiota. However, the emergence of certain EEC subtypes depends on tissue maturation. Finally, our integrative approach infers lineage-specific regulators dynamically, identifying new candidates controlling EEC differentiation in the developing human gut.

Enteroendocrine cells (EECs) are rare intestinal epithelial cells producing multiple hormones that regulate essential aspects of digestion and energy. EEC subtypes, their hormone repertoire and differentiation mechanisms from intestinal stem cells have been characterized in the adult intestine. However, although EECs need to be functional from birth, as their absence causes severe intestinal malabsorption in newborns, the mechanisms underlying EEC subtype specification during development are largely unknown. We used mouse embryos, human pluripotent stem cell derived intestinal organoid models and single-cell transcriptomics to characterize EEC lineages and dynamics during development. Our findings demonstrate that in both mice and humans, the majority of EECs are specified during development through similar differentiation trajectories as observed in the adult intestine. This suggests that EEC subtypes specification occurs independently of fully organized crypt-villus structures and stimulation by diet or microbiota. However, the emergence of certain EEC subtypes depends on tissue maturation. Finally, our integrative approach infers lineage-specific regulators dynamically, identifying new candidates controlling EEC differentiation in the developing human gut. Most enteroendocrine cells (EECs) are specified during development. Crypt-villus organization, diet or microbiota are not essential for EEC formation. In pluripotent stem cell derived human intestinal organoids (HIOs), EECs differentiate along 3 main trajectories, one driven by maturation processes. Novel Gene Regulatory Networks are identified governing human EEC differentiation in HIOs.

Objective: Enteroendocrine cells (EECs) of the gastro-intestinal tract sense gut luminal factors and release peptide hormones or serotonin (5-HT) to coordinate energy uptake and storage. Our goal is to decipher the gene regulatory networks controlling EECs specification from enteroendocrine progenitors. In this context, we studied the role of the transcription factor Rfx6 which had been identified as the cause of Mitchell-Riley syndrome characterized by neonatal diabetes and congenital malabsorptive diarrhea. We previously reported that Rfx6 was essential for pancreatic beta cell development and function, however, the role of Rfx6 in EECs differentiation remained to be elucidated. Methods: We examined the molecular, cellular and metabolic consequences of constitutive and conditional deletion of Rfx6 in the embryonic and adult mouse intestine. We performed single cell and bulk RNA-Seq to characterize EECs diversity and identify Rfx6-regulated genes. Results: Rfx6 is expressed in the gut endoderm; later it is turned on in, and restricted to, enteroendocrine progenitors and persists in hormone-positive EECs. In the embryonic intestine, the constitutive lack of Rfx6 leads to gastric heterotopia, suggesting a role in the maintenance of intestinal identity. In the absence of intestinal Rfx6, EECs differentiation is severely impaired both in the embryo and adult. However, the number of serotonin-producing enterochromaffin cells and mucosal 5-HT content are increased. Concomitantly, Neurog3-positive enteroendocrine progenitors accumulate. Combined analysis of single-cell and bulk RNA-Seq data revealed that enteroendocrine progenitors differentiate in two main cell trajectories, the enterochromaffin (EC) cells and the Peptidergic Enteroendocrine (PE) cells, whose differentiation programs are differentially regulated by Rfx6. Rfx6 operates upstream of Arx, Pax6 and Isl1 to trigger the differentiation of peptidergic EECs such as GIP-, GLP-1- or CCK-secreting cells. On the contrary, Rfx6 represses Lmx1a and Tph1, two genes essential for serotonin biosynthesis. Finally, we identified transcriptional changes uncovering adaptive responses to the prolonged lack of enteroendocrine hormones and leading to malabsorption and lower food efficiency ratio in Rfx6-deficient mouse intestine. Conclusion: These studies identify Rfx6 as an essential transcriptional regulator of EECs specification and shed light on the molecular mechanisms of intestinal failures in human RFX6-deficiencies such as Mitchell-Riley syndrome.

Localization of mRNAs to neuronal terminals, coupled to local translation, has emerged as a prevalent mechanism controlling the synaptic proteome. However, the physiological regulation and function of this process in the context of mature in vivo memory circuits has remained unclear. Here, we combined synaptosome RNA profiling with whole brain high-resolution imaging to uncover mRNAs with different localization patterns in the axons of Drosophila Mushroom Body memory neurons, some exhibiting regionalized, input-dependent, recruitment along axons. By integrating transcriptome-wide binding approaches and functional assays, we show that the conserved Imp RNA binding protein controls the transport of mRNAs to Mushroom Body axons and characterize a mutant in which this transport is selectively impaired. Using this unique mutant, we demonstrate that axonal mRNA localization is required for long-term, but not short-term, behavioral memory. This work uncovers circuit-dependent mRNA targeting in vivo and demonstrates the importance of local RNA regulation in memory consolidation. Axonal transcriptomes have been characterized, but their regulation and role in neuronal circuits remain unclear. Here authors uncover activity-dependent RNA localization in axons important for memory consolidation.

Background Tick-borne lymphadenopathy (TIBOLA) is a tick-borne disease transmitted by Dermacentor ticks and is usually caused by Rickettsia . In 2021, clinicians in northeastern France reported an increase in TIBOLA cases. Methods This entomo-clinical, multicenter, retrospective, and observational study aimed to describe the evolution of the number of TIBOLA cases between 2016 and 2021 in northeastern France as well as the evolution of the Dermacentor tick population. Results A total of 35 cases of TIBOLA were identified, 16 of which occurred in 2021, with clear predominance in April and May. A longitudinal study performed in the Alsace region (endemic for ticks and tick-borne diseases) revealed a peak in tick activity in 2021. A trend toward an increase in TIBOLA cases in 2021 in the northeastern region of France was observed, as was an increase in the Dermacentor tick population in some biotopes. Conclusions TIBOLA appears to be an emerging disease that should be monitored, as should the Dermacentor population. Graphical Abstract

A novel coronavirus, SARS-CoV-2, was first reported as a respiratory illness in December 2019 in Wuhan, China. Since then, the World Health Organization (WHO) Emergency Committee declared a global health. COVID-19 has now spread worldwide and is responsible of more than 472,216 persons, out of 9,100,090 officially diagnosed worldwide since 23 of June. In the context of cancer patients, COVID-19 has a severe impact, regarding pulmonary infection but also cancer treatments in this fragile and immunocompromised population, and ICU admission for cancer patients in the context of COVID-19 requires ethical and clinical consideration. In our cancer center, intensivists, oncologists, pharmacists, and hospital administrators had to prepare for a substantial increase in critical care bed capacity (from 10 ICU beds, 6 medical intensive care beds, and 12 surgical intensive care beds, bed capacity was increased to 28 medical intensive care beds with ventilating capacity) and to adapt infrastructure (i.e., ICU beds), supplies (i.e., drugs, ventilators, protective materials), and staff (i.e., nurses and medical staff). Overall, thirty-three COVID-19 patients were admitted in our ICU, 17 cancer-free and 16 with cancer, and 23 required mechanical ventilation, resulting in 4 deaths (of them two patients with cancer). We report here management of a dedicated intensive care unit of a cancer center during the COVID-19 infection pandemic, considering resource allocation and redistribution of healthcare workers.

To conduct a comprehensive analysis of prospectively measured circulating high sensitivity C reactive protein (hsCRP) concentration and risk of lung cancer overall, by smoking status (never, former, and current smokers), and histological sub-type. Nested case-control study. 20 population based cohort studies in Asia, Europe, Australia, and the United States. 5299 patients with incident lung cancer, with individually incidence density matched controls. Circulating hsCRP concentrations in prediagnostic serum or plasma samples. Incident lung cancer diagnosis. A positive association between circulating hsCRP concentration and the risk of lung cancer for current (odds ratio associated with a doubling in hsCRP concentration 1.09, 95% confidence interval 1.05 to 1.13) and former smokers (1.09, 1.04 to 1.14) was observed, but not for never smokers (P<0.01 for interaction). This association was strong and consistent across all histological subtypes, except for adenocarcinoma, which was not strongly associated with hsCRP concentration regardless of smoking status (odds ratio for adenocarcinoma overall 0.97, 95% confidence interval 0.94 to 1.01). The association between circulating hsCRP concentration and the risk of lung cancer was strongest in the first two years of follow-up for former and current smokers. Including hsCRP concentration in a risk model, in addition to smoking based variables, did not improve risk discrimination overall, but slightly improved discrimination for cancers diagnosed in the first two years of follow-up. Former and current smokers with higher circulating hsCRP concentrations had a higher risk of lung cancer overall. Circulating hsCRP concentration was not associated with the risk of lung adenocarcinoma. Circulating hsCRP concentration could be a prediagnostic marker of lung cancer rather than a causal risk factor.

Although ferrocene ketones have been known since the early days of ferrocene chemistry, their behavior in deprotometalation has never been studied in detail. Here, we have optimized this reaction using lithium 2,2,6,6-tetramethylpiperidide in tetrahydrofuran containing ZnCl2·N,N,N',N'-tetramethylethylenediamine as an in-situ trap. Numerous 2-iodoferrocene derivatives were obtained, while a change in regioselectivity was observed for certain aroyl- and heteroaroylferrocenes, in good agreement with our DFT calculations. The development of an enantioselective deprotometalation was also attempted using lithium di[(S)-1-phenylethyl]amide, affording the desired compounds in up to 60% enantiomeric excess (ee). A selection of iodinated derivatives was finally subjected to post-functionalizations, leading to original ferrocene-fused heterocycles, including an enantiopure tetracyclic derivative. A selection of compounds was studied in both electrochemical reduction and oxidation, and weak interactions such as halogen–halogen, halogen–oxygen and chalcogen–chalcogen bonds were identified in the solid state for some new derivatives.

Neuronal ceroid lipofuscinoses (NCLs) represent the most common group of inherited progressive encephalopathies in children. They are characterized by progressive loss of vision, mental and motor deterioration, epileptic seizures, and premature death. Rare adult forms of NCL with late onset are known as Kufs' disease. Loci underlying these adult forms remain unknown due to the small number of patients and genetic heterogeneity. Here we confirm that a late-onset form of NCL recessively segregates in US and French pedigrees of American Staffordshire Terrier (AST) dogs. Through combined association, linkage, and haplotype analyses, we mapped the disease locus to a single region of canine chromosome 9. We eventually identified a worldwide breed-specific variant in exon 2 of the Arylsulfatase G (ARSG) gene, which causes a p.R99H substitution in the vicinity of the catalytic domain of the enzyme. In transfected cells or leukocytes from affected dogs, the missense change leads to a 75% decrease in sulfatase activity, providing a functional confirmation that the variant might be the NCL-causing mutation. Our results uncover a protein involved in neuronal homeostasis, identify a family of candidate genes to be screened in patients with Kufs' disease, and suggest that a deficiency in sulfatase is part of the NCL pathogenesis.

Single germline nucleotide pathogenic variants have been identified in 12 breast cancer predisposition genes, but structural deletions in these genes remain poorly characterized. We conducted in-depth whole genome sequencing (WGS) in genomic DNA samples obtained from 1340 invasive breast cancer cases and 675 controls of African ancestry. We identified 25 deletions in the intragenic regions of ten established breast cancer predisposition genes based on a consensus call from six state-of-the-art SV callers. Overall, no significant case–control difference was found in the frequency of these deletions. However, 1.0% of cases and 0.3% of controls carried any of the eight putative protein-truncating rare deletions located in BRCA1, BRCA2, CDH1, TP53, NF1, RAD51D, RAD51C and CHEK2, resulting in an odds ratio (OR) of 3.29 (95% CI 0.74–30.16). We also identified a low-frequency deletion in NF1 associated with breast cancer risk (OR 1.93, 95% CI 1.14–3.42). In addition, we detected 56 deletions, including six putative protein-truncating deletions, in suspected breast predisposition genes. This is the first large study to systematically search for structural deletions in breast cancer predisposition genes. Many of the deletions, particularly those resulting in protein truncations, are likely to be pathogenic. Results from this study, if confirmed in future large-scale studies, could have significant implications for genetic testing for this common cancer.