Deleterious effect of sustained neuroinflammation in pediatric traumatic brain injury

INTRODUCTION

Despite improved management of traumatic brain injury (TBI), it still leads to lifelong sequelae and disability, particularly in children. Chronic neuroinflammation (the so-called tertiary phase), in particular, microglia/macrophage and astrocyte reactivity, is among the main mechanisms suspected of playing a role in the generation of lesions associated with TBI. The role of acute neuroinflammation is now well understood, but its persistent effect and impact on the brain, particularly during development, are not. Here, we investigated the long-term effects of pediatric TBI on the brain in a mouse model.

METHODS

Pediatric TBI was induced in mice on postnatal day (P) 7 by weight-drop trauma. The time course of neuroinflammation and myelination was examined in the TBI mice. They were also assessed by magnetic resonance, functional ultrasound, and behavioral tests at P45.

RESULTS

TBI induced robust neuroinflammation, characterized by acute microglia/macrophage and astrocyte reactivity. The long-term consequences of pediatric TBI studied on P45 involved localized scarring astrogliosis, persistent microgliosis associated with a specific transcriptomic signature, and a long-lasting myelination defect consisting of the loss of myelinated axons, a decreased level of myelin binding protein, and severe thinning of the corpus callosum. These results were confirmed by reduced fractional anisotropy, measured by diffusion tensor imaging, and altered inter- and intra-hemispheric connectivity, measured by functional ultrasound imaging. In addition, adolescent mice with pediatric TBI showed persistent social interaction deficits and signs of anxiety and depressive behaviors.

CONCLUSIONS

We show that pediatric TBI induces tertiary neuroinflammatory processes associated with white matter lesions and altered behavior. These results support our model as a model for preclinical studies for tertiary lesions following TBI.

An AluYa5 Insertion in the 3'UTR of COL4A1 and Cerebral Small Vessel Disease

Importance

Cerebral small vessel diseases (CSVDs) account for one-fifth of stroke cases. Numerous familial cases remain unresolved after routine screening of known CSVD genes.

Objective

To identify novel genes and mechanisms associated with familial CSVD.

Design, Setting, and Participants

This 2-stage study involved linkage analysis and a case-control study; linkage analysis and whole exome and genome sequencing were used to identify candidate gene variants in 2 large families with CSVD (9 patients with CSVD). Then, a case-control analysis was conducted on 246 unrelated probands, including probands from these 2 families and 244 additional probands. All probands (clinical onset

Main Outcomes and Measures

A pathogenic AluYa5 insertion was identified within the COL4A1 3'UTR in the 2 large families with CSVD. Reverse transcriptase-quantitative polymerase chain reaction (RT-qPCR), Western blot, and long-read RNA sequencing were used to investigate outcomes associated with the insertion using patient fibroblasts. Clinical and magnetic resonance imaging features of probands with variants and available relatives were assessed.

Results

Among 246 probands (141 females [57.3%]; median [IQR] age at referral, 56 [49-64] years), 7 patients of French ancestry carried the insertion. This insertion was absent in 467 healthy French individuals in a control group (odds ratio, ∞; 95% CI, 2.78 to ∞; P = 5 × 10-4) and 10 847 individuals from the gnomAD structural variant database (odds ratio, ∞; 95% CI, 64.77 to ∞; P = 2.42 × 10-12). In these 7 patients' families, 19 family members with CSVD carried the insertion. RT-qPCR and Western blot showed an upregulation of COL4A1 mRNA (10.6-fold increase; 95% CI, 1.4-fold to 17.1-fold increase) and protein levels (2.8-fold increase; 95% CI, 2.1-fold to 3.5-fold increase) in patient vs control group fibroblasts. Long-read RNA sequencing data showed that the insertion was associated with perturbation in the use of canonical COL4A1 polyadenylation signals (approximately 87% of isoforms transcribed from the wild type allele vs 5% of isoforms transcribed from the allele with the insertion used the 2 distal canonical polyadenylation signals). The main clinical feature of individuals with CSVD was the recurrence of pontine ischemic lesions starting at an early age (17 of 19 patients [89.5%]).

Conclusions and relevance

This study found a novel mechanism associated with COL4A1 upregulation and a highly penetrant adult-onset CSVD. These findings suggest that quantitative alterations of the cerebrovascular matrisome are associated with CSVD pathogenesis, with diagnostic and therapeutic implications.

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MESH Headings

• Adult
• Female
• Humans
• Middle Aged
• 3' Untranslated Regions/genetics
• Alleles
• Case-Control Studies
• Cerebral Small Vessel Diseases/genetics
• Collagen Type IV/metabolism
• Protein Isoforms
• Mutagenesis, Insertional

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Affiliation(s)

Chaker Aloui NeuroDiderot, Université Paris Cité, Institut National de la Santé Et de la Recherche Médicale, Unité Mixte de Recherche 1141, Paris, France
Lisa Neumann NeuroDiderot, Université Paris Cité, Institut National de la Santé Et de la Recherche Médicale, Unité Mixte de Recherche 1141, Paris, France
Françoise Bergametti NeuroDiderot, Université Paris Cité, Institut National de la Santé Et de la Recherche Médicale, Unité Mixte de Recherche 1141, Paris, France
Eric Sartori Service de Neurologie, Centre Hospitalier Bretagne Sud, Lorient, France
Marc Herbreteau Service de Neurologie, Centre Hospitalier Bretagne Sud, Lorient, France
Arnaud Maillard Assistance Publique-Hôpitaux de Paris, Service de Génétique Moléculaire Neurovasculaire, Hôpital Saint-Louis, Paris, France
Thibault Coste NeuroDiderot, Université Paris Cité, Institut National de la Santé Et de la Recherche Médicale, Unité Mixte de Recherche 1141, Paris, France Assistance Publique-Hôpitaux de Paris, Service de Génétique Moléculaire Neurovasculaire, Hôpital Saint-Louis, Paris, France
Hélène Morel NeuroDiderot, Université Paris Cité, Institut National de la Santé Et de la Recherche Médicale, Unité Mixte de Recherche 1141, Paris, France Assistance Publique-Hôpitaux de Paris, Service de Génétique Moléculaire Neurovasculaire, Hôpital Saint-Louis, Paris, France
Dominique Hervé NeuroDiderot, Université Paris Cité, Institut National de la Santé Et de la Recherche Médicale, Unité Mixte de Recherche 1141, Paris, France Assistance Publique-Hôpitaux de Paris, Service de Neurologie, Hôpital Lariboisière, Paris, France
Hugues Chabriat NeuroDiderot, Université Paris Cité, Institut National de la Santé Et de la Recherche Médicale, Unité Mixte de Recherche 1141, Paris, France Assistance Publique-Hôpitaux de Paris, Service de Neurologie, Hôpital Lariboisière, Paris, France
Serge Timsit Service de Neurologie Vasculaire, Centre Hospitalier Régional Universitaire de Brest, Brest, France
Irina Viakhireva Service de Neurologie Vasculaire, Centre Hospitalier Régional Universitaire de Brest, Brest, France
Yves Denoyer Service de Neurologie, Centre Hospitalier Bretagne Sud, Lorient, France Université de Rennes, Laboratoire Traitement du Signal et de l'Image, Institut National de la Santé Et de la Recherche Médicale Unité Mixte de Recherche 1099, Rennes, France
Rémi Allibert Service de Neurologie, Unité Neurovasculaire, Centre Hospitalier Universitaire de Saint Etienne, Saint Etienne, France
Florence Demurger Service de Neurologie, Unité Neurovasculaire, Centre Hospitalier Bretagne Atlantique, Vannes, France
Cedric Gollion Service de Neurologie, Centre Hospitalier Universitaire de Toulouse, Toulouse, France
Patrick Vermersch Univ. Lille, Institut National de la Santé Et de la Recherche Médicale Unité Mixte de Recherche 1172 LilNCog, Centre Hospitalier Universitaire Lille, Fédérations Hospitalo-Universitaire Precise, Lille, France
Florence Marchelli Assistance Publique-Hôpitaux de Paris, Service de Génétique Moléculaire Neurovasculaire, Hôpital Saint-Louis, Paris, France
Corinne Blugeon GenomiqueENS, Institut de Biologie de l’Ecole Normale Supérieur, Département de biologie, École Normale Supérieure, Centre National de la Recherche Scientifique, Institut National de la Santé Et de la Recherche Médicale, Université Paris Sciences et Lettres, Paris, France
Sophie Lemoine GenomiqueENS, Institut de Biologie de l’Ecole Normale Supérieur, Département de biologie, École Normale Supérieure, Centre National de la Recherche Scientifique, Institut National de la Santé Et de la Recherche Médicale, Université Paris Sciences et Lettres, Paris, France
Claire Tourtier-Bellosta Service de Neurologie, Centre Hospitalier Bretagne Sud, Lorient, France
Alexis Brouazin Service de neurologie, Centre Hospitalier de Cornouaille, Quimper, France
Anne-Louise Leutenegger NeuroDiderot, Université Paris Cité, Institut National de la Santé Et de la Recherche Médicale, Unité Mixte de Recherche 1141, Paris, France
Eva Pipiras NeuroDiderot, Université Paris Cité, Institut National de la Santé Et de la Recherche Médicale, Unité Mixte de Recherche 1141, Paris, France Assistance Publique-Hôpitaux de Paris, Hôpitaux Jean Verdier et Armand Trousseau, Université Sorbonne Paris Nord, Bobigny, France
Elisabeth Tournier-Lasserve NeuroDiderot, Université Paris Cité, Institut National de la Santé Et de la Recherche Médicale, Unité Mixte de Recherche 1141, Paris, France Assistance Publique-Hôpitaux de Paris, Service de Génétique Moléculaire Neurovasculaire, Hôpital Saint-Louis, Paris, France

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Blood Monocyte Phenotype Is A Marker of Cardiovascular Risk in Type 2 Diabetes

BACKGROUND

Diabetes is a major risk factor for atherosclerotic cardiovascular diseases with a 2-fold higher risk of cardiovascular events in people with diabetes compared with those without. Circulating monocytes are inflammatory effector cells involved in both type 2 diabetes (T2D) and atherogenesis.

METHODS

We investigated the relationship between circulating monocytes and cardiovascular risk progression in people with T2D, using phenotypic, transcriptomic, and metabolomic analyses. cardiovascular risk progression was estimated with coronary artery calcium score in a cohort of 672 people with T2D.

RESULTS

Coronary artery calcium score was positively correlated with blood monocyte count and frequency of the classical monocyte subtype. Unsupervised k-means clustering based on monocyte subtype profiles revealed 3 main endotypes of people with T2D at varying risk of cardiovascular events. These observations were confirmed in a validation cohort of 279 T2D participants. The predictive association between monocyte count and major adverse cardiovascular events was validated through an independent prospective cohort of 757 patients with T2D. Integration of monocyte transcriptome analyses and plasma metabolomes showed a disruption of mitochondrial pathways (tricarboxylic acid cycle, oxidative phosphorylation pathway) that underlined a proatherogenic phenotype.

CONCLUSIONS

In this study, we provide evidence that frequency and monocyte phenotypic profile are closely linked to cardiovascular risk in patients with T2D. The assessment of monocyte frequency and count is a valuable predictive marker for risk of cardiovascular events in patients with T2D.

REGISTRATION

URL: https://www.clinicaltrials.gov; Unique identifier: NCT04353869.

2022 Recommendations of the AFU Lithiasis Committee: Medical management - from diagnosis to treatment

The morphological-compositional analysis of urinary stones allows distinguishing schematically several situations: dietary, digestive, metabolic/hormonal, infectious and genetic problems. Blood and urine testing are recommended in the first instance to identify risk factors of urinary stone disease in order to avoid recurrence or progression. The other objective is to detect a potential underlying pathology associated with high risk of urinary stone disease (e.g. primary hyperparathyroidism, primary or enteric hyperoxaluria, cystinuria, distal renal tubular acidosis) that may require specific management. Lifestyle-diet measures are the basis of the management of all stone types, but pharmacological treatments may be required. METHODOLOGY: These recommendations were developed using two methods: the Clinical Practice Recommendation (CPR) method and the ADAPTE method, depending on whether the question was considered in the European Association of Urology (EAU) recommendations (https://uroweb.org/guidelines/urolithiasis) [EAU 2022] and their adaptability to the French context.

A unique cerebellar pattern of microglia activation in a mouse model of encephalopathy of prematurity

Preterm infants often show pathologies of the cerebellum, which are associated with impaired motor performance, lower IQ and poor language skills at school ages. Using a mouse model of inflammation-induced encephalopathy of prematurity driven by systemic administration of pro-inflammatory IL-1β, we sought to uncover causes of cerebellar damage. In this model, IL-1β is administered between postnatal day (P) 1 to day 5, a timing equivalent to the last trimester for brain development in humans. Structural MRI analysis revealed that systemic IL-1β treatment induced specific reductions in gray and white matter volumes of the mouse cerebellar lobules I and II (5% false discovery rate [FDR]) from P15 onwards. Preceding these MRI-detectable cerebellar volume changes, we observed damage to oligodendroglia, with reduced proliferation of OLIG2+ cells at P10 and reduced levels of the myelin proteins myelin basic protein (MBP) and myelin-associated glycoprotein (MAG) at P10 and P15. Increased density of IBA1+ cerebellar microglia were observed both at P5 and P45, with evidence for increased microglial proliferation at P5 and P10. Comparison of the transcriptome of microglia isolated from P5 cerebellums and cerebrums revealed significant enrichment of pro-inflammatory markers in microglia from both regions, but cerebellar microglia displayed a unique type I interferon signaling dysregulation. Collectively, these data suggest that perinatal inflammation driven by systemic IL-1β leads to specific cerebellar volume deficits, which likely reflect oligodendrocyte pathology downstream of microglial activation. Further studies are now required to confirm the potential of protective strategies aimed at preventing sustained type I interferon signaling driven by cerebellar microglia as an important therapeutic target.

Early macrophage response to obesity encompasses Interferon Regulatory Factor 5 regulated mitochondrial architecture remodelling

Adipose tissue macrophages (ATM) adapt to changes in their energetic microenvironment. Caloric excess, in a range from transient to diet-induced obesity, could result in the transition of ATMs from highly oxidative and protective to highly inflammatory and metabolically deleterious. Here, we demonstrate that Interferon Regulatory Factor 5 (IRF5) is a key regulator of macrophage oxidative capacity in response to caloric excess. ATMs from mice with genetic-deficiency of Irf5 are characterised by increased oxidative respiration and mitochondrial membrane potential. Transient inhibition of IRF5 activity leads to a similar respiratory phenotype as genomic deletion, and is reversible by reconstitution of IRF5 expression. We find that the highly oxidative nature of Irf5-deficient macrophages results from transcriptional de-repression of the mitochondrial matrix component Growth Hormone Inducible Transmembrane Protein (GHITM) gene. The Irf5-deficiency-associated high oxygen consumption could be alleviated by experimental suppression of Ghitm expression. ATMs and monocytes from patients with obesity or with type-2 diabetes retain the reciprocal regulatory relationship between Irf5 and Ghitm. Thus, our study provides insights into the mechanism of how the inflammatory transcription factor IRF5 controls physiological adaptation to diet-induced obesity via regulating mitochondrial architecture in macrophages.

Interferon Regulatory Factor 5 levels have been shown to increase in adipose tissue macrophages in diet-induced obesity. Here authors show that IRF5 transcriptionally represses the Growth Hormone Inducible Transmembrane Protein gene encoding a mitochondrial protein important for oxidative respiration in macrophages, thus driving the detrimental metabolic changes observed in obesity.

Comparative transcriptome analysis of goat (Capra hircus) adipose tissue reveals physiological regulation of body reserve recovery after the peak of lactation

Adipose tissue is the energy storage organ providing energy to other tissues, including mammary gland, that supports the achievement of successive lactation cycles. Our objective was to investigate the ability of goats to restore body fat reserves by comparing lipogenic enzyme activities and by transcriptomic RNA-Seq data at two different physiological stages, mid- and post-lactation. Key lipogenic enzyme activities were higher in goat omental adipose tissue during mid-lactation (74 days in milk) than during the post-lactation period (300 days postpartum). RNA-Sequencing analysis revealed 19,271 expressed genes in the omental adipose tissue. The comparison between adipose transcriptome analysis from mid- and post-lactation goats highlighted 252 differentially expressed genes (p_adj < 0.05) between these two physiological stages. The differential expression of 11 genes was confirmed by RT-qPCR. Functional genomic analysis revealed that 31% were involved in metabolic processes among which 38% in lipid metabolism. Most of the genes involved in lipid synthesis and those in lipid transport and storage were upregulated in adipose tissue of mid- compared to post-lactation goats. In addition, adipose tissue plasticity was emphasized by genes involved in cellular signaling and tissue integrity. Network analyses also highlighted three key regulators of lipid metabolism (LEP, APOE and HNF4A) and a key target gene (VCAM1). The greatest lipogenic enzyme activities with the upregulation of genes involved in lipid metabolism highlighted a higher recovery of lipid reserves after the lactation peak than 4 months post-lactation. This study contributes to a better understanding of the molecular mechanisms controlling the body lipid reserves management during the successive lactations.

Regulatory T Cells Expressing Tumor Necrosis Factor Receptor Type 2 Play a Major Role in CD4+ T-Cell Impairment During Sepsis

Sepsis causes inflammation-induced immunosuppression with lymphopenia and alterations of CD4+ T-cell functions that renders the host prone to secondary infections. Whether and how regulatory T cells (Treg) are involved in this postseptic immunosuppression is unknown. We observed in vivo that early activation of Treg during Staphylococcus aureus sepsis induces CD4+ T-cell impairment and increases susceptibility to secondary pneumonia. The tumor necrosis factor receptor 2 positive (TNFR2pos) Treg subset endorsed the majority of effector immunosuppressive functions, and TNRF2 was particularly associated with activation of genes involved in cell cycle and replication in Treg, probably explaining their maintenance. Blocking or deleting TNFR2 during sepsis decreased the susceptibility to secondary infection. In humans, our data paralleled those in mice; the expression of CTLA-4 was dramatically increased in TNFR2pos Treg after culture in vitro with S. aureus. Our findings describe in vivo mechanisms underlying sepsis-induced immunosuppression and identify TNFR2pos Treg as targets for therapeutic intervention.

The Tumor Microenvironment Impairs Th1 IFNγ Secretion through Alternative Splicing Modifications of Irf1 Pre-mRNA

It is clearly established that the immune system can affect cancer response to therapy. However, the influence of the tumor microenvironment (TME) on immune cells is not completely understood. In this respect, alternative splicing is increasingly described to affect the immune system. Here, we showed that the TME, via a TGFβ-dependent mechanism, increased alternative splicing events and induced the expression of an alternative isoform of the IRF1 transcription factor (IRF1Δ7) in Th1 cells. We found that the SFPQ splicing factor (splicing factor, proline- and glutamine-rich) was responsible for the IRF1Δ7 production. We also showed, in both mice and humans, that the IRF1 alternative isoform altered the full-length IRF1 transcriptional activity on the Il12rb1 promoter, resulting in decreased IFNγ secretion in Th1 cells. Thus, the IRF1Δ7 isoform was increased in the TME, and inhibiting IRF1Δ7 expression could potentiate Th1 antitumor responses.

Adipocyte Reprogramming by the Transcriptional Coregulator GPS2 Impacts Beta Cell Insulin Secretion

Glucose homeostasis is maintained through organ crosstalk that regulates secretion of insulin to keep blood glucose levels within a physiological range. In type 2 diabetes, this coordinated response is altered, leading to a deregulation of beta cell function and inadequate insulin secretion. Reprogramming of white adipose tissue has a central role in this deregulation, but the critical regulatory components remain unclear. Here, we demonstrate that expression of the transcriptional coregulator GPS2 in white adipose tissue is correlated with insulin secretion rate in humans. The causality of this relationship is confirmed using adipocyte-specific GPS2 knockout mice, in which inappropriate secretion of insulin promotes glucose intolerance. This phenotype is driven by adipose-tissue-secreted factors, which cause increased pancreatic islet inflammation and impaired beta cell function. Thus, our study suggests that, in mice and in humans, GPS2 controls the reprogramming of white adipocytes to influence pancreatic islet function and insulin secretion.

Dynamic nanopore long-read sequencing analysis of HIV-1 splicing events during the early steps of infection

Background

Alternative splicing is a key step in Human Immunodeficiency Virus type 1 (HIV-1) replication that is tightly regulated both temporally and spatially. More than 50 different transcripts can be generated from a single HIV-1 unspliced pre-messenger RNA (pre-mRNA) and a balanced proportion of unspliced and spliced transcripts is critical for the production of infectious virions. Understanding the mechanisms involved in the regulation of viral RNA is therefore of potential therapeutic interest. However, monitoring the regulation of alternative splicing events at a transcriptome-wide level during cell infection is challenging. Here we used the long-read cDNA sequencing developed by Oxford Nanopore Technologies (ONT) to explore in a quantitative manner the complexity of the HIV-1 transcriptome regulation in infected primary CD4+ T cells.

Results

ONT reads mapping to the viral genome proved sufficiently long to span all possible splice junctions, even distant ones, and to be assigned to a total of 150 exon combinations. Fifty-three viral RNA isoforms, including 14 new ones were further considered for quantification. Relative levels of viral RNAs determined by ONT sequencing showed a high degree of reproducibility, compared favourably to those produced in previous reports and highly correlated with quantitative PCR (qPCR) data. To get further insights into alternative splicing regulation, we then compiled quantifications of splice site (SS) usage and transcript levels to build “splice trees”, a quantitative representation of the cascade of events leading to the different viral isoforms. This approach allowed visualizing the complete rewiring of SS usages upon perturbation of SS D2 and its impact on viral isoform levels. Furthermore, we produced the first dynamic picture of the cascade of events occurring between 12 and 24 h of viral infection. In particular, our data highlighted the importance of non-coding exons in viral RNA transcriptome regulation.

Conclusion

ONT sequencing is a convenient and reliable strategy that enabled us to grasp the dynamic of the early splicing events modulating the viral RNA landscape in HIV-1 infected cells.

Loss of G protein pathway suppressor 2 in human adipocytes triggers lipid remodeling by upregulating ATP binding cassette subfamily G member 1

OBJECTIVE

Adipogenesis is critical for adipose tissue remodeling during the development of obesity. While the role of transcription factors in the orchestration of adipogenic pathways is already established, the involvement of coregulators that transduce regulatory signals into epigenome alterations and transcriptional responses remains poorly understood. The aim of our study was to investigate which pathways are controlled by G protein pathway suppressor 2 (GPS2) during the differentiation of human adipocytes.

METHODS

We generated a unique loss-of-function model by RNAi depletion of GPS2 in human multipotent adipose-derived stem (hMADS) cells. We thoroughly characterized the coregulator depletion-dependent pathway alterations during adipocyte differentiation at the level of transcriptome (RNA-seq), epigenome (ChIP-seq H3K27ac), cistrome (ChIP-seq GPS2), and lipidome. We validated the in vivo relevance of the identified pathways in non-diabetic and diabetic obese patients.

RESULTS

The loss of GPS2 triggers the reprogramming of cellular processes related to adipocyte differentiation by increasing the responses to the adipogenic cocktail. In particular, GPS2 depletion increases the expression of BMP4, an important trigger for the commitment of fibroblast-like progenitors toward the adipogenic lineage and increases the expression of inflammatory and metabolic genes. GPS2-depleted human adipocytes are characterized by hypertrophy, triglyceride and phospholipid accumulation, and sphingomyelin depletion. These changes are likely a consequence of the increased expression of ATP-binding cassette subfamily G member 1 (ABCG1) that mediates sphingomyelin efflux from adipocytes and modulates lipoprotein lipase (LPL) activity. We identify ABCG1 as a direct transcriptional target, as GPS2 depletion leads to coordinated changes of transcription and H3K27 acetylation at promoters and enhancers that are occupied by GPS2 in wild-type adipocytes. We find that in omental adipose tissue of obese humans, GPS2 levels correlate with ABCG1 levels, type 2 diabetic status, and lipid metabolic status, supporting the in vivo relevance of the hMADS cell-derived in vitro data.

CONCLUSION

Our study reveals a dual regulatory role of GPS2 in epigenetically modulating the chromatin landscape and gene expression during human adipocyte differentiation and identifies a hitherto unknown GPS2-ABCG1 pathway potentially linked to adipocyte hypertrophy in humans.

Pediatric victims involved in urban fires in Paris and its suburbs: Epidemiology, prehospital care, and lessons learned

AIM

The literature includes few reports on the prehospital care of pediatric casualties of urban house fires. Here we aimed to describe the epidemiology of pediatric fire victims, focusing on their injuries, prehospital care, and survival.

METHODS

This retrospective study included children under 15 years of age who were victims of urban house fires and who received care from prehospital medical teams. The variables analyzed included epidemiology, specific care provided by prehospital emergency services, the number of cardiac arrests, and survival rates.

RESULTS

Over the 15-month study period, 365 house fires required the presence of at least one prehospital medical team. Casualties of these fires included 121 pediatric victims (median age, 4 years [interquartile range: 2-9 years]). All children were initially treated by a prehospital medical team that was not specialized in pediatrics. Six children (4.9%) received secondary treatment from a pediatric support team. Of the 121 children, 114 (94.2%) suffered from smoke inhalation and seven (5.8%) from burns. Two patients who were in cardiac arrest at their initial medical care did not survive.

CONCLUSION

Pediatric fire casualties were initially managed by prehospital medical teams that were not specialized in pediatrics. As in adults, the main injuries were secondary to smoke inhalation, but this has increased toxicity in children. Prehospital teams not specialized in pediatrics can optimize their practice via the sharing of experiences, team training, and cognitive aid checklist for pediatric fire victims.

Composition of urinary calculi: Lessons from a French epidemiologic retrospective study

INTRODUCTION

Urolithiasis is a common urological disease whose incidence increases in developed countries. We studied relations between composition of urinary calculi, age and gender.

MATERIAL

An epidemiologic study was conducted in a French population of patients encountered analysis of urinary calculi between 2013 and 2017. This retrospective cohort study was performed from urinary calculi samples analysed in a clinical biochemistry laboratory of University Hospital of Lyon in France. A total of 5782 samples were included. Data, according to stone composition, presence of a papillary umbilication and a Randall's plaque, age and gender, were investigated. Statistical analyses used the Chi² test (R software).

RESULTS

The overall male to female sex ratio was equal to 1.76. The average and the median of age were 52.1 and 53.0 years, respectively. Whewellite was the most frequent main component in our population (44.4%). Carbapatite, weddellite and uric acid represented the main component in 14.0%, 13.4% and 13.0% of samples, respectively. Differences between genders were shown. Whewellite and uric acid were more frequent in men (P<0.001), while carbapatite and struvite were predominant in women (P<0.001).

CONCLUSIONS

Our study provided recent data on the composition of urinary calculi in a French population and the relations between composition of urinary calculi and age and gender.

LEVEL OF EVIDENCE

3.

Molecular characterisation of a cellular conveyor belt in Clytia medusae

The tentacular system of Clytia hemisphaerica medusa (Cnidaria, Hydrozoa) has recently emerged as a promising experimental model to tackle the developmental mechanisms that regulate cell lineage progression in an early-diverging animal phylum. From a population of proximal stem cells, the successive steps of tentacle stinging cell (nematocyte) elaboration, are spatially ordered along a "cellular conveyor belt". Furthermore, the C. hemisphaerica tentacular system exhibits bilateral organisation, with two perpendicular polarity axes (proximo-distal and oral-aboral). We aimed to improve our knowledge of this cellular system by combining RNAseq-based differential gene expression analyses and expression studies of Wnt signalling genes. RNAseq comparisons of gene expression levels were performed (i) between the tentacular system and a control medusa deprived of all tentacles, nematogenic sites and gonads, and (ii) between three samples staggered along the cellular conveyor belt. The behaviour in these differential expression analyses of two reference gene sets (stem cell genes; nematocyte genes), as well as the relative representations of selected gene ontology categories, support the validity of the cellular conveyor belt model. Expression patterns obtained by in situ hybridisation for selected highly differentially expressed genes and for Wnt signalling genes are largely consistent with the results from RNAseq. Wnt signalling genes exhibit complex spatial deployment along both polarity axes of the tentacular system, with the Wnt/β-catenin pathway probably acting along the oral-aboral axis rather than the proximo-distal axis. These findings reinforce the idea that, despite overall radial symmetry, cnidarians have a full potential for elaboration of bilateral structures based on finely orchestrated deployment of an ancient developmental gene toolkit.

Arabidopsis S2Lb links AtCOMPASS-like and SDG2 activity in H3K4me3 independently from histone H2B monoubiquitination

Background

The functional determinants of H3K4me3, their potential dependency on histone H2B monoubiquitination, and their contribution to defining transcriptional regimes are poorly defined in plant systems. Unlike in Saccharomyces cerevisiae, where a single SET1 protein catalyzes H3K4me3 as part of COMPlex of proteins ASsociated with Set1 (COMPASS), in Arabidopsis thaliana, this activity involves multiple histone methyltransferases. Among these, the plant-specific SET DOMAIN GROUP 2 (SDG2) has a prominent role.

Results

We report that SDG2 co-regulates hundreds of genes with SWD2-like b (S2Lb), a plant ortholog of the Swd2 axillary subunit of yeast COMPASS. We show that S2Lb co-purifies with the AtCOMPASS core subunit WDR5, and both S2Lb and SDG2 directly influence H3K4me3 enrichment over highly transcribed genes. S2Lb knockout triggers pleiotropic developmental phenotypes at the vegetative and reproductive stages, including reduced fertility and seed dormancy. However, s2lb seedlings display little transcriptomic defects as compared to the large repertoire of genes targeted by S2Lb, SDG2, or H3K4me3, suggesting that H3K4me3 enrichment is important for optimal gene induction during cellular transitions rather than for determining on/off transcriptional status. Moreover, unlike in budding yeast, most of the S2Lb and H3K4me3 genomic distribution does not rely on a trans-histone crosstalk with histone H2B monoubiquitination.

Conclusions

Collectively, this study unveils that the evolutionarily conserved COMPASS-like complex has been co-opted by the plant-specific SDG2 histone methyltransferase and mediates H3K4me3 deposition through an H2B monoubiquitination-independent pathway in Arabidopsis.

Electronic supplementary material

The online version of this article (10.1186/s13059-019-1705-4) contains supplementary material, which is available to authorized users.

Not only disease activity but also chronic hypertension and overweight are determinants of pregnancy outcomes in patients with systemic lupus erythematosus

INTRODUCTION

Pregnancies in women with lupus nephritis are at high-risk of complications, while scarcity of scientific knowledge on prognostic factors impedes a fair medical counseling. We aimed to identify determinants associated with maternal and fetal complications.

MATERIALS

We retrospectively reviewed medical charts of pregnancies that lasted more than 22 weeks in 66 patients with pre-existing lupus nephritis between 2004 and 2013 in France. Univariate and multivariate analyses were conducted to identify determinants for maternal complications, lupus renal flare and fetal prematurity or death.

RESULTS

Eighty-four pregnancies were identified. A maternal complication occurred in 31 pregnancies (36.9%): mostly preeclampsia (17 pregnancies, 20.2%) and renal flares (12 pregnancies, 14.3%). Overall fetal survival was 94.0% (79/84). Maternal pregnancy complications were independently associated with prepregnancy body mass index >25 kg/m² (OR 3.81, 95% CI 1.03-14.09) and immunological activity (positive anti-dsDNA antibodies or Farr assay lupus) (OR 4.95, 95% CI 1.33-18.43). Renal lupus flares were independently associated with maternal age (OR 1.50, 95% CI 1.12-2.01) and prepregnancy immunological activity (OR 15.99, 95% CI 1.57-162.68) while a remission time >12 months had a protective effect (OR 0.17, 95% CI 0.04-0.68). Three parameters were associated with a higher risk of fetal prematurity or death: a prepregnancy body mass index >25 kg/m² (HR 3.58, 95% CI 1.45-8.83), hypertension (HR 8.97, 95% CI 3.32-24.25), and immunological activity (HR 3.34, 95% CI 1.30-8.63).

CONCLUSION

Maternal age, prepregnancy hypertension, body mass index >25 kg/m² and lupus immunological activity may be considered as the main determinants for fetal and maternal complications. A remission time above 12 months for patients with lupus nephritis could be associated with a reduced risk of renal flare during pregnancy.

Cellular Origin, Tumor Progression, and Pathogenic Mechanisms of Cutaneous Neurofibromas Revealed by Mice with Nf1 Knockout in Boundary Cap Cells

Patients carrying an inactive NF1 allele develop tumors of Schwann cell origin called neurofibromas (NF). Genetically engineered mouse models have significantly enriched our understanding of plexiform forms of NFs (pNF). However, this has not been the case for cutaneous neurofibromas (cNF), observed in all NF1 patients, as no previous model recapitulates their development. Here, we show that conditional Nf1 inactivation in Prss56-positive boundary cap cells leads to bona fide pNFs and cNFs. This work identifies subepidermal glia as a likely candidate for the cellular origin of cNFs and provides insights on disease mechanisms, revealing a long, multistep pathologic process in which inflammation-related signals play a pivotal role. This new mouse model is an important asset for future clinical and therapeutic investigations of NF1-associated neurofibromas. SIGNIFICANCE: Patients affected by NF1 develop numerous cNFs. We present a mouse model that faithfully recapitulates cNFs, identify a candidate cell type at their origin, analyze the steps involved in their formation, and show that their development is dramatically accelerated by skin injury. These findings have important clinical/therapeutic implications.This article is highlighted in the In This Issue feature, p. 1.

Aozan: an automated post-sequencing data-processing pipeline

Motivation

Data management and quality control of output from Illumina sequencers is a disk space- and time-consuming task. Thus, we developed Aozan to automatically handle data transfer, demultiplexing, conversion and quality control once a run has finished. This software greatly improves run data management and the monitoring of run statistics via automatic emails and HTML web reports.

Availability and Implementation

Aozan is implemented in Java and Python, supported on Linux systems, and distributed under the GPLv3 License at: http://www.outils.genomique.biologie.ens.fr/aozan/ . Aozan source code is available on GitHub: https://github.com/GenomicParisCentre/aozan .

Contact

aozan@biologie.ens.fr.

Quaking RNA-Binding Proteins Control Early Myofibril Formation by Modulating Tropomyosin

Skeletal muscle contraction is mediated by myofibrils, complex multi-molecular scaffolds structured into repeated units, the sarcomeres. Myofibril structure and function have been extensively studied, but the molecular processes regulating its formation within the differentiating muscle cell remain largely unknown. Here we show in zebrafish that genetic interference with the Quaking RNA-binding proteins disrupts the initial steps of myofibril assembly without affecting early muscle differentiation. Using RNA sequencing, we demonstrate that Quaking is required for accumulation of the muscle-specific tropomyosin-3 transcript, tpm3.12. Further functional analyses reveal that Tpm3.12 mediates Quaking control of myofibril formation. Moreover, we identified a Quaking-binding site in the 3' UTR of tpm3.12 transcript, which is required in vivo for tpm3.12 accumulation and myofibril formation. Our work uncovers a Quaking/Tpm3 pathway controlling de novo myofibril assembly. This unexpected developmental role for Tpm3 could be at the origin of muscle defects observed in human congenital myopathies associated with tpm3 mutation.

Rehabilitation of distal radioulnar joint instability

Distal radioulnar joint (DRUJ) instabilities are common and often combined with other injuries of the interosseous membrane and/or the proximal radioulnar joint. Once they are diagnosed and the treatment is chosen, physiotherapists have limited choices due to the lack of validated protocols. The benefits of proprioception and neuromuscular rehabilitation have been brought to light for the shoulder, knee and ankle joints, among others. However, no program has been described for the DRUJ. The purpose of this article is to study the muscular elements responsible for active DRUJ stability, and to propose a proprioceptive rehabilitation program suited to this condition.

Chronic Lyme borreliosis associated with minimal change glomerular disease: a case report

BACKGROUND

There are only few cases of renal pathology induced by Lyme borreliosis in the literature, as this damage is rare and uncommon in humans. This patient is the first case of minimal change glomerular disease associated with chronic Lyme borreliosis.

CASE PRESENTATION

A 65-year-old Caucasian woman was admitted for an acute edematous syndrome related to a nephrotic syndrome. Clinical examination revealed violaceous skin lesions of the right calf and the gluteal region that occurred 2 years ago. Serological tests were positive for Lyme borreliosis and skin biopsy revealed lesions of chronic atrophic acrodermatitis. Renal biopsy showed minimal change glomerular disease. The skin lesions and the nephrotic syndrome resolved with a sequential treatment with first ceftriaxone and then corticosteroids.

CONCLUSION

We report here the first case of minimal change disease associated with Lyme borreliosis. The pathogenesis of minimal change disease in the setting of Lyme disease is discussed but the association of Lyme and minimal change disease may imply a synergistic effect of phenotypic and bacterial factors. Regression of proteinuria after a sequential treatment with ceftriaxone and corticosteroids seems to strengthen this conceivable association.

Genome sequencing and transcriptome analysis of Trichoderma reesei QM9978 strain reveals a distal chromosome translocation to be responsible for loss of vib1 expression and loss of cellulase induction

BACKGROUND

The hydrolysis of biomass to simple sugars used for the production of biofuels in biorefineries requires the action of cellulolytic enzyme mixtures. During the last 50 years, the ascomycete Trichoderma reesei, the main source of industrial cellulase and hemicellulase cocktails, has been subjected to several rounds of classical mutagenesis with the aim to obtain higher production levels. During these random genetic events, strains unable to produce cellulases were generated. Here, whole genome sequencing and transcriptomic analyses of the cellulase-negative strain QM9978 were used for the identification of mutations underlying this cellulase-negative phenotype.

RESULTS

Sequence comparison of the cellulase-negative strain QM9978 to the reference strain QM6a identified a total of 43 mutations, of which 33 were located either close to or in coding regions. From those, we identified 23 single-nucleotide variants, nine InDels, and one translocation. The translocation occurred between chromosomes V and VII, is located upstream of the putative transcription factor vib1, and abolishes its expression in QM9978 as detected during the transcriptomic analyses. Ectopic expression of vib1 under the control of its native promoter as well as overexpression of vib1 under the control of a strong constitutive promoter restored cellulase expression in QM9978, thus confirming that the translocation event is the reason for the cellulase-negative phenotype. Gene deletion of vib1 in the moderate producer strain QM9414 and in the high producer strain Rut-C30 reduced cellulase expression in both cases. Overexpression of vib1 in QM9414 and Rut-C30 had no effect on cellulase production, most likely because vib1 is already expressed at an optimal level under normal conditions.

CONCLUSION

We were able to establish a link between a chromosomal translocation in QM9978 and the cellulase-negative phenotype of the strain. We identified the transcription factor vib1 as a key regulator of cellulases in T. reesei whose expression is absent in QM9978. We propose that in T. reesei, as in Neurospora crassa, vib1 is involved in cellulase induction, although the exact mechanism remains to be elucidated. The data presented here show an example of a combined genome sequencing and transcriptomic approach to explain a specific trait, in this case the QM9978 cellulase-negative phenotype, and how it helps to better understand the mechanisms during cellulase gene regulation. When focusing on mutations on the single base-pair level, changes on the chromosome level can be easily overlooked and through this work we provide an example that stresses the importance of the big picture of the genomic landscape during analysis of sequencing data.

IRF5 governs liver macrophage activation that promotes hepatic fibrosis in mice and humans

Hepatic fibrosis arises from inflammation in the liver initiated by resident macrophage activation and massive leukocyte accumulation. Hepatic macrophages hold a central position in maintaining homeostasis in the liver and in the pathogenesis of acute and chronic liver injury linked to fibrogenesis. Interferon regulatory factor 5 (IRF5) has recently emerged as an important proinflammatory transcription factor involved in macrophage activation under acute and chronic inflammation. Here, we revealed that IRF5 is significantly induced in liver macrophages from human subjects developing liver fibrosis from nonalcoholic fatty liver disease or hepatitis C virus infection. Furthermore, IRF5 expression positively correlated with clinical markers of liver damage, such as plasma transaminase and bilirubin levels. Interestingly, mice lacking IRF5 in myeloid cells (MKO) were protected from hepatic fibrosis induced by metabolic or toxic stresses. Transcriptional reprogramming of macrophages lacking IRF5 was characterized by immunosuppressive and antiapoptotic properties. Consequently, IRF5 MKO mice respond to hepatocellular stress by promoting hepatocyte survival, leading to complete protection from hepatic fibrogenesis. Our findings reveal a regulatory network, governed by IRF5, that mediates hepatocyte death and liver fibrosis in mice and humans. Therefore, modulating IRF5 function may be an attractive approach to experimental therapeutics in fibroinflammatory liver disease.

Estimated or Measured GFR in Living Kidney Donors Work-up?

The value of estimated glomerular filtration rate (eGFR) in living kidney donors screening is unclear. A recently published web-based application derived from large cohorts, but not living donors, calculates the probability of a measured GFR (mGFR) lower than a determined threshold. Our objectives were to validate the clinical utility of this tool in a cohort of living donors and to test two other strategies based on chronic kidney disease epidemiology collaboration (CKD-EPI) and on MDRD-eGFR. GFR was measured using ⁵¹ Cr- ethylene-diamine tetraacetic acid urinary clearance in 311 potential living kidney donors (178 women, mean age 50 ± 11.6 years). The web-based tool was used to predict those with mGFR < 80 mL/min/1.73 m² . Inputs to the application were sex, age, ethnicity, and plasma creatinine. In our cohort, a web-based probability of mGFR <90 mL/min/1.73 m² higher than 2% had 100% sensitivity for detection of actual mGFR <80 mL/min/1.73 m² . The positive predictive value was 0.19. A CKD-EPI-eGFR threshold of 104 mL/min/1.73 m² and an MDRD-eGFR threshold of 100 mL/min/1.73 m² had 100% sensitivity to detect donors with actual mGFR <80 mL/min/1.73 m² . We obtained similar results in an external cohort of 354 living donors. We confirm the usefulness of the web-based application to identify potential donors who should benefit from GFR measurement.