Search Results Heading

MBRLSearchResults

mbrl.module.common.modules.added.book.to.shelf
Title added to your shelf!
View what I already have on My Shelf.
Oops! Something went wrong.
Oops! Something went wrong.
While trying to add the title to your shelf something went wrong :( Kindly try again later!
Are you sure you want to remove the book from the shelf?
Oops! Something went wrong.
Oops! Something went wrong.
While trying to remove the title from your shelf something went wrong :( Kindly try again later!
    Done
    Filters
    Reset
  • Discipline
      Discipline
      Clear All
      Discipline
  • Is Peer Reviewed
      Is Peer Reviewed
      Clear All
      Is Peer Reviewed
  • Item Type
      Item Type
      Clear All
      Item Type
  • Subject
      Subject
      Clear All
      Subject
  • Year
      Year
      Clear All
      From:
      -
      To:
  • More Filters
20 result(s) for "Allain, Charlotte"
Sort by:
A point mutation in suppressor of cytokine signalling 2 (Socs2) increases the susceptibility to inflammation of the mammary gland while associated with higher body weight and size and higher milk production in a sheep model
Mastitis is an infectious disease mainly caused by bacteria invading the mammary gland. Genetic control of susceptibility to mastitis has been widely evidenced in dairy ruminants, but the genetic basis and underlying mechanisms are still largely unknown. We describe the discovery, fine mapping and functional characterization of a genetic variant associated with elevated milk leukocytes count, or SCC, as a proxy for mastitis. After implementing genome-wide association studies, we identified a major QTL associated with SCC on ovine chromosome 3. Fine mapping of the region, using full sequencing with 12X coverage in three animals, provided one strong candidate SNP that mapped to the coding sequence of a highly conserved gene, suppressor of cytokine signalling 2 (Socs2). The frequency of the SNP associated with increased SCC was 21.7% and the Socs2 genotype explained 12% of the variance of the trait. The point mutation induces the p.R96C substitution in the SH2 functional domain of SOCS2 i.e. the binding site of the protein to various ligands, as well-established for the growth hormone receptor GHR. Using surface plasmon resonance we showed that the p.R96C point mutation completely abrogates SOCS2 binding affinity for the phosphopeptide of GHR. Additionally, the size, weight and milk production in p.R96C homozygote sheep, were significantly increased by 24%, 18%, and 4.4%, respectively, when compared to wild type sheep, supporting the view that the point mutation causes a loss of SOCS2 functional activity. Altogether these results provide strong evidence for a causal mutation controlling SCC in sheep and highlight the major role of SOCS2 as a tradeoff between the host's inflammatory response to mammary infections, and body growth and milk production, which are all mediated by the JAK/STAT signaling pathway.
Genome-wide analyses reveal a strong association between LEPR gene variants and body fat reserves in ewes
Background Among the adaptive capacities of animals, the management of energetic body reserves (BR) through the BR mobilization and accretion processes (BR dynamics, BRD) has become an increasingly valuable attribute for livestock sustainability, allowing animals to cope with more variable environments. BRD has previously been reported to be heritable in ruminants. In the present work, we conducted genome-wide studies (GWAS) in sheep to determine genetic variants associated with BRD. BR (i.e. levels) and BRD (i.e. changes over time) were obtained through body condition score measurements at eight physiological stages throughout each productive cycle in Romane ewes ( n  = 1034) and were used as phenotypes for GWAS. After quality controls and imputation, 48,593 single nucleotide polymorphisms (SNP) were included in the GWAS. Results Among the 23 QTL regions identified, a major QTL associated with BR during pregnancy and lactation was identified on chromosome 1. In this region, several significant SNPs mapped to the leptin receptor gene (LEPR), among which one SNP mapped to the coding sequence. The point mutation induces the p.P1019S substitution in the cytoplasmic domain, close to tyrosine phosphorylation sites. The frequency of the SNP associated with increased BR levels was 32%, and the LEPR genotype explained up to 5% of the variance of the trait. Higher fatness levels in ewes carrying the LEPR p.P1019S mutation were observed all along the productive cycle. Conclusions These results provide strong evidences for involvement of LEPR in the regulation of BR in sheep and highlight it as a major candidate gene for improving adaptive capacities by genetic selection.
Whole blood transcriptome analysis reveals potential competition in metabolic pathways between negative energy balance and response to inflammatory challenge
Negative Energy Balance (NEB) is considered to increase susceptibility to mastitis. The objective of thisstudy was to improve our understanding of the underlying mechanisms by comparing transcriptomicprofiles following NEB and a concomitant mammary inflammation. Accordingly, we performed RNAseqanalysis of blood cells in energy-restricted ewes and control-diet ewes at four different time pointsbefore and after intra mammary challenge with phlogogenic ligands. Blood leucocytes respondedto NEB by shutting down lipid-generating processes, including cholesterol and fatty acid synthesis,probably under transcriptional control of SREBF 1. Furthermore, fatty acid oxidation was activated andglucose oxidation and transport inhibited in response to energy restriction. Among the differentiallyexpressed genes (DEGs) in response to energy restriction, 64 genes were also differential in responseto the inflammatory challenge. Opposite response included the activation of cholesterol and fatty acidsynthesis during the inflammatory challenge. Moreover, activation of glucose oxidation and transportcoupled with the increase of plasma glucose concentration in response to the inflammatory stimulisuggested a preferential utilization of glucose as the energy source during this stress. Leucocytemetabolism therefore undergoes strong metabolic changes during an inflammatory challenge, whichcould be in competition with those induced by energy restriction.
A validation study of loci associated with mastitis resistance in two French dairy sheep breeds
Background: The identification of loci associated with resistance to mastitis or of the causative mutations may be helpful in breeding programs for dairy sheep as it is for cattle worldwide. Seven genomic regions that control milk somatic cell counts, an indirect indicator of udder infection, have already been identified in sheep (Spanish Churra, French Lacaune and Italian Sardinian–Lacaune backcross populations). In this study, we used a 960 custom-designed ovine single nucleotide polymorphism (SNP) chip in Lacaune and Manech Tête Rousse dairy sheep to validate these seven genomic regions associated with mastitis.Results: The most significant SNP (rs868996547) on Ovis aries chromosome (OAR) 3 was a previously described mutation in the suppressor of cytokine signalling 2 (SOCS2) gene. An antagonist effect of this causal candidate between health and growth in Lacaune sheep was confirmed. Effects of the mutation on the infectious status of the udder, i.e. increases in milk somatic cell counts and bacteria shedding, were also identified. This SNP was not present in the data available on Manech Tête Rousse. Three other regions associated with mastitis were also confirmed on OAR16 (Manech Tête Rousse), 19 (Lacaune) and 2 (both breeds). For the OAR2 region, we validated previously detected SNPs in several other breeds (Sarda, Churra, and Chios). For significant SNPs in the four mastitis regions, the effect varied from 0.24 to 0.67 phenotypic standard deviation of the traits. Two of the mastitis quantitative trait loci (QTL) regions (OAR2 and 16) that we validated here were also associated in opposite ways with milk production traits in both populations.Conclusions: These results indicate, at least in part, a genomic basis for the trade-off between milk production and mastitis resistance. Four of the seven mastitis QTL regions that were previously identified in independent populations, were confirmed in this study, which demonstrates partial sharing of mastitis-related genetic mechanisms between different distant dairy sheep populations.
Complete investigations (autopsy, toxicology, and histology) in a death due to apixaban overdose
The dead body of a 54-year-old man was found at home by his partner. He was off work due to depression. A letter with suicidal intention was present on the scene. He was known to be a heavy drinker, and near the body, an empty bottle of whisky was found. In addition, 2 empty blisters of Eliquis (apixaban) 5 mg, corresponding to 40 tablets, were identified. Apixaban is an oral anticoagulant, acting as a factor Xa inhibitor. Autopsy findings were mostly unremarkable, except numerous bruises and some superficial self-inflected wounds. Histology showed hematomas of calyces and renal pelvis and in the liver, several areas of perivenular haemorrhagic necrosis. Others organs were congestive. Femoral venous blood alcohol was 0.11 g/L. In femoral venous blood, a toxic concentration of apixaban was measured at 1184 ng/mL using LC-MS/MS. Other drugs found at therapeutic concentrations included diazepam (99 ng/mL), nordiazepam (171 ng/mL), flecainide (447 ng/mL), and mianserine (65 ng/mL). Using liquid chromatography coupled to high-resolution mass spectrometry, 2 metabolites were identified, O-desmethyl-apixaban (61.8% of the apixaban response) and hydroxyl-apixaban (4.5% of the apixaban response). Long-term therapy was confirmed by a concentration of 10390 pg/mg in pubic hair.
Fatal penetrating iliac wound: A case report with determination of physical activity and time to collapse
A case of fatal left iliac penetrating wound in a thirty-year-old man, during a fight, was presented. The medical file described a transfixing five-centimeter large wound on the left iliac vein and a puncture wound on the left iliac artery. After performing an autopsy, we concluded that the death was secondary to multivisceral failure, secondary to hemorrhagic shock. The judge investigating the case requested a detailed forensic medical reconstructive opinion focusing on the sequence of events leading to the fatal blow. Our having access to the videorecording and the photographs of the crime scene, added to the testimonies of witnesses proved to be a great help to the investigation. The data from the crime scene video recordings allowed us to estimate the victim's physical activity after the fatal stabbing (running between 20 and 140 meters) and the time when he collapsed (between 32s and 1 min) after the stabbing which is rarely described with methods using Closed-Circuit Television material, especially in cases of fatal vascular injuries. Those data are usually estimated from eyewitnesses’ accounts, which remain an unreliable method. •Using CTTV cameras allow documenting physical activity after fatal vascular injury.•In vascular injuries the vital prognosis depends largely on the venous lesions.•Further importance of the blood traces photography and vascular lesions description.
A Nonsense Variant in CCDC65 Gene Causes Respiratory Failure Associated with Increased Lamb Mortality in French Lacaune Dairy Sheep
We recently demonstrated that the Lacaune deficient homozygous haplotype 6 (LDHH6) potentially hosts a recessive perinatal lethal mutation in Lacaune dairy sheep mapped on OAR3. In the present study, we have analyzed the whole-genome sequences of two Lacaune ram heterozygous carriers of LDHH6. After variant calling and filtering against the variants of 86 non-carrier rams, we have identified a single nucleotide variant (SNV) in the two LDHH6 carriers whose variant allele induced a premature stop codon (p.Glu111*) in the Coiled-Coil Domain Containing 65 (CCDC65) gene. CCDC65 is involved in the assembly of the nexin-dynein regulatory complex for the formation of microtubules in ciliated cells. In order to identify the phenotype in homozygous sheep, we generated at-risk matings (n = 17) between rams and ewes heterozygous for the candidate variant in CCDC65. A total of 16 lambs were born alive with five genotyped as homozygous carriers. The homozygous lambs suffered from respiratory problems, and four of them died within the first month of life. At necropsy, we observed a broad hepatization of lung lobes possibly induced by infectious pneumonia. The management of this lethal recessive allele (frequency of 0.06) through reasoned mating in the Lacaune sheep selection schemes could reduce lamb mortality by 2%.
A Point Mutation in Suppressor of Cytokine Signalling 2 ( Socs2 ) Increases the Susceptibility to Inflammation of the Mammary Gland while Associated with Higher Body Weight and Size and Higher Milk Production in a Sheep Model
Mastitis is an infectious disease mainly caused by bacteria invading the mammary gland. Genetic control of susceptibility to mastitis has been widely evidenced in dairy ruminants, but the genetic basis and underlying mechanisms are still largely unknown. We describe the discovery, fine mapping and functional characterization of a genetic variant associated with elevated milk leukocytes count, or SCC, as a proxy for mastitis. After implementing genome-wide association studies, we identified a major QTL associated with SCC on ovine chromosome 3. Fine mapping of the region, using full sequencing with 12X coverage in three animals, provided one strong candidate SNP that mapped to the coding sequence of a highly conserved gene, suppressor of cytokine signalling 2 (Socs2). The frequency of the SNP associated with increased SCC was 21.7% and the Socs2 genotype explained 12% of the variance of the trait. The point mutation induces the p.R96C substitution in the SH2 functional domain of SOCS2 i.e. the binding site of the protein to various ligands, as well-established for the growth hormone receptor GHR. Using surface plasmon resonance we showed that the p.R96C point mutation completely abrogates SOCS2 binding affinity for the phosphopeptide of GHR. Additionally, the size, weight and milk production in p.R96C homozygote sheep, were significantly increased by 24%, 18%, and 4.4%, respectively, when compared to wild type sheep, supporting the view that the point mutation causes a loss of SOCS2 functional activity. Altogether these results provide strong evidence for a causal mutation controlling SCC in sheep and highlight the major role of SOCS2 as a tradeoff between the host's inflammatory response to mammary infections, and body growth and milk production, which are all mediated by the JAK/STAT signaling pathway.
Ferroquine, the next generation antimalarial drug, has antitumor activity
Despite the tremendous progress in medicine, cancer remains one of the most serious global health problems awaiting new effective therapies. Here we present ferroquine (FQ), the next generation antimalarial drug, as a promising candidate for repositioning as cancer therapeutics. We report that FQ potently inhibits autophagy, perturbs lysosomal function and impairs prostate tumor growth in vivo . We demonstrate that FQ negatively regulates Akt kinase and hypoxia-inducible factor-1α (HIF-1α) and is particularly effective in starved and hypoxic conditions frequently observed in advanced solid cancers. FQ enhances the anticancer activity of several chemotherapeutics suggesting its potential application as an adjuvant to existing anticancer therapy. Alike its parent compound chloroquine (CQ), FQ accumulates within and deacidifies lysosomes. Further, FQ induces lysosomal membrane permeabilization, mitochondrial depolarization and caspase-independent cancer cell death. Overall, our work identifies ferroquine as a promising new drug with a potent anticancer activity.
Base-editing mutagenesis maps alleles to tune human T cell functions
CRISPR-enabled screening is a powerful tool for the discovery of genes that control T cell function and has nominated candidate targets for immunotherapies 1 – 6 . However, new approaches are required to probe specific nucleotide sequences within key genes. Systematic mutagenesis in primary human T cells could reveal alleles that tune specific phenotypes. DNA base editors are powerful tools for introducing targeted mutations with high efficiency 7 , 8 . Here we develop a large-scale base-editing mutagenesis platform with the goal of pinpointing nucleotides that encode amino acid residues that tune primary human T cell activation responses. We generated a library of around 117,000 single guide RNA molecules targeting base editors to protein-coding sites across 385 genes implicated in T cell function and systematically identified protein domains and specific amino acid residues that regulate T cell activation and cytokine production. We found a broad spectrum of alleles with variants encoding critical residues in proteins including PIK3CD, VAV1, LCP2, PLCG1 and DGKZ, including both gain-of-function and loss-of-function mutations. We validated the functional effects of many alleles and further demonstrated that base-editing hits could positively and negatively tune T cell cytotoxic function. Finally, higher-resolution screening using a base editor with relaxed protospacer-adjacent motif requirements 9 (NG versus NGG) revealed specific structural domains and protein–protein interaction sites that can be targeted to tune T cell functions. Base-editing screens in primary immune cells thus provide biochemical insights with the potential to accelerate immunotherapy design. Massive-scale mutational screening across 385 genes reveals a wide spectrum of alleles that govern tunable T cell functions, including cytokine production and cytotoxicity.