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result(s) for
"Pinard, Amélie"
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Comparative genomics of emerging pathogens in the Candida glabrata clade
by
Marcet-Houben, Marina
,
Dujon, Bernard
,
Hennequin, Christophe
in
Adaptations
,
Animal Genetics and Genomics
,
Biochemistry, Molecular Biology
2013
Background
Candida glabrata
follows
C. albicans
as the second or third most prevalent cause of candidemia worldwide. These two pathogenic yeasts are distantly related,
C. glabrata
being part of the
Nakaseomyces
, a group more closely related to
Saccharomyces cerevisiae.
Although
C. glabrata
was thought to be the only pathogenic
Nakaseomyces
, two new pathogens have recently been described within this group:
C. nivariensis
and
C. bracarensis
. To gain insight into the genomic changes underlying the emergence of virulence, we sequenced the genomes of these two, and three other non-pathogenic
Nakaseomyces
, and compared them to other sequenced yeasts
.
Results
Our results indicate that the two new pathogens are more closely related to the non-pathogenic
N. delphensis
than to
C. glabrata.
We uncover duplications and accelerated evolution that specifically affected genes in the lineage preceding the group containing
N. delphensis
and the three pathogens, which may provide clues to the higher propensity of this group to infect humans. Finally, the number of Epa-like adhesins is specifically enriched in the pathogens, particularly in
C. glabrata
.
Conclusions
Remarkably, some features thought to be the result of adaptation of
C. glabrata
to a pathogenic lifestyle
,
are present throughout the
Nakaseomyces,
indicating these are rather ancient adaptations to other environments. Phylogeny suggests that human pathogenesis evolved several times, independently within the clade. The expansion of the
EPA
gene family in pathogens establishes an evolutionary link between adhesion and virulence phenotypes. Our analyses thus shed light onto the relationships between virulence and the recent genomic changes that occurred within the
Nakaseomyces
.
Sequence Accession Numbers
Nakaseomyces delphensis
: CAPT01000001 to CAPT01000179
Candida bracarensis
: CAPU01000001 to CAPU01000251
Candida nivariensis
: CAPV01000001 to CAPV01000123
Candida castellii
: CAPW01000001 to CAPW01000101
Nakaseomyces bacillisporus
: CAPX01000001 to CAPX01000186
Journal Article
Variations in the poly-histidine repeat motif of HOXA1 contribute to bicuspid aortic valve in mouse and zebrafish
2023
Bicuspid aortic valve (BAV), the most common cardiovascular malformation occurs in 0.5–1.2% of the population. Although highly heritable, few causal mutations have been identified in BAV patients. Here, we report the targeted sequencing of
HOXA1
in a cohort of BAV patients and the identification of rare indel variants in the homopolymeric histidine tract of HOXA1. In vitro analysis shows that disruption of this motif leads to a significant reduction in protein half-life and defective transcriptional activity of HOXA1. In zebrafish, targeting
hoxa1a
ortholog results in aortic valve defects. In vivo assays indicates that these variants behave as dominant negatives leading abnormal valve development. In mice, deletion of
Hoxa1
leads to BAV with a very small, rudimentary non-coronary leaflet. We also show that 17% of homozygous
Hoxa1
−1His
knock-in mice present similar phenotype. Genetic lineage tracing in
Hoxa1
−/−
mutant mice reveals an abnormal reduction of neural crest-derived cells in the valve leaflet, which is caused by a failure of early migration of these cells.
Bicuspid aortic valve (BAV) is the most common cardiac defect and although highly heritable, few causal mutations have been identified. Here, the authors identify variants in the poly-histidine repeat motif of HOXA1 and show that its disruption leads to BAV in mice.
Journal Article
The pleiotropy associated with de novo variants in CHD4, CNOT3, and SETD5 extends to moyamoya angiopathy
2020
Moyamoya angiopathy (MMA) is a cerebrovascular disease characterized by occlusion of large arteries, which leads to strokes starting in childhood. Twelve altered genes predispose to MMA but the majority of cases of European descent do not have an identified genetic trigger.
Exome sequencing from 39 trios were analyzed.
We identified four de novo variants in three genes not previously associated with MMA: CHD4, CNOT3, and SETD5. Identification of additional rare variants in these genes in 158 unrelated MMA probands provided further support that rare pathogenic variants in CHD4 and CNOT3 predispose to MMA. Previous studies identified de novo variants in these genes in children with developmental disorders (DD), intellectual disability, and congenital heart disease.
These genes encode proteins involved in chromatin remodeling, and taken together with previously reported genes leading to MMA-like cerebrovascular occlusive disease (YY1AP1, SMARCAL1), implicate disrupted chromatin remodeling as a molecular pathway predisposing to early onset, large artery occlusive cerebrovascular disease. Furthermore, these data expand the spectrum of phenotypic pleiotropy due to alterations of CHD4, CNOT3, and SETD5 beyond DD to later onset disease in the cerebrovascular arteries and emphasize the need to assess clinical complications into adulthood for genes associated with DD.
Journal Article
A novel USP51 variant in a patient with autism spectrum disorder and epilepsy
2024
Autism spectrum disorder (ASD) is a highly heritable neurodevelopmental disorder characterized by impaired social communication and repetitive behaviours. The genetic basis of ASD is complex and involves both rare variants with large effect sizes and common variants with small effect sizes. Based on current knowledge, the variant is predicted to result in a truncated protein and is considered a variant of uncertain significance (VUS). The USP51 gene has been implicated in neurodevelopment, and its role in the developing brain suggests its potential relevance to ASD. Further studies are needed to establish the association of USP51 variants with ASD and elucidate the full phenotypic spectrum associated with these variants.
Journal Article
Rare deleterious variants of NOTCH1, GATA4, SMAD6, and ROBO4 are enriched in BAV with early onset complications but not in BAV with heritable thoracic aortic disease
by
Bamshad, Michael J.
,
Guo, Dongchuan
,
Nickerson, Deborah A.
in
Aneurysms
,
Aorta
,
Aortic aneurysms
2020
Background Bicuspid aortic valve (BAV) is the most common cardiovascular malformation in adults, with a prevalence of 0.5%–2%. The prevalence of BAV in cohorts who were ascertained due to thoracic aortic aneurysms or acute aortic dissections (TAD) is as high as 20%. However, the contribution of causal BAV genes to TAD is not known. Therefore, we evaluated rare deleterious variants of GATA4, NOTCH1, SMAD6, or ROBO4 in patients with BAV who presented with TAD. Methods Our cohort consisted of 487 probands with Heritable Thoracic Aortic Aneurysms or Dissections (HTAD, 12% BAV, 29% female) and 63 probands with Early onset complications of Bicuspid Aortic Valve disease (EBAV, 63% TAD, 34% female). After whole exome sequencing, we functionally annotated GATA4, NOTCH1, SMAD6, and ROBO4 variants and compared the prevalence of rare variants in these genes to controls without HTAD. Results We identified 11 rare deleterious variants of GATA4, SMAD6, or ROBO4 in 12 (18%) EBAV cases. The burden of rare SMAD6 and GATA4 variants was significantly enriched in EBAV but not in HTAD cases, even among HTAD cases with BAV (p < .003). Conclusion Rare variants of NOTCH1, ROBO4, SMAD6, or GATA4 do not significantly contribute to BAV in cohorts with HTAD. We conclude that BAV patients who present with HTAD are a genetically distinct subgroup with implications for genetic testing and prognosis. Bicuspid aortic valve (BAV) is the most common congenital heart defect in adults and is a frequent risk factor for heritable thoracic aortic aneurysms predisposing to acute aortic dissections (HTAD). To elucidate the roles of known causal BAV genes in HTAD, we determined if individuals who present with both BAV and HTAD harbor an increased burden of rare deleterious variants in NOTCH1, GATA4, SMAD6 or ROBO4. We found that variants of these genes do not significantly contribute to HTAD, even in cases with BAV. These results indicate that BAV patients who present due to complications of HTAD have markedly different genetic and clinical profiles than BAV patients who present due to valvular heart disease. Therefore, additional factors are probably required to drive clinically meaningful enlargement and dissection of aneurysms in BAV patients.
Journal Article
Analysis of HOXB1 gene in a cohort of patients with sporadic ventricular septal defect
by
Bonnet, Damien
,
Mitchell, Julia
,
Eudes, Nathalie
in
Coronary artery disease
,
Etiology
,
Genetic diversity
2018
Ventricular septal defect (VSD) including outlet VSD of double outlet right ventricle (DORV) and perimembranous VSD are among the most common congenital heart diseases found at birth. HOXB1 encodes a homeodomain transcription factor essential for normal cardiac outflow tract development. The aim of the present study was to investigate the possible genetic effect of sequence variations in HOXB1 on VSD. The coding regions and splice junctions of the HOXB1 gene were sequenced in 57 unrelated VSD patients. As a result, a homozygous c.74_82dup (p.Pro28delinsHisSerAlaPro) variant was identified in one individual with DORV. We also identified five previously reported polymorphisms (rs35114525, rs12946855, rs14534040, rs12939811, and rs7207109) in 18 patients (12 DORV and 6 perimembranous VSD). Our study did not show any pathogenic alterations in the coding region of HOXB1 among patients with VSD. To our knowledge this is the first study investigating the role of HOXB1 in nonsyndromic VSD, which provide more insight on the etiology of this disease.
Journal Article
A genome-wide search for new imprinted genes in the human placenta identifies DSCAM as the first imprinted gene on chromosome 21
by
Laïla Allach El Khattabi
,
Vaiman, Daniel
,
Jammes, Hélène
in
Chromosome 21
,
Down's syndrome
,
DSCAM protein
2019
We identified, through a genome-wide search for new imprinted genes in the human placenta, DSCAM (Down Syndrome Cellular Adhesion Molecule) as a paternally expressed imprinted gene. Our work revealed the presence of a Differentially Methylated Region (DMR), located within intron 1 that might regulate the imprinting in the region. This DMR showed a maternal allele methylation, compatible with its paternal expression. We showed that DSCAM is present in endothelial cells and the syncytiotrophoblast layer of the human placenta. In mouse, Dscam expression is biallelic in foetal brain and placenta excluding any possible imprinting in these tissues. This gene encodes a cellular adhesion molecule mainly known for its role in neurone development but its function in the placenta remains unclear. We report here the first imprinted gene located on human chromosome 21 with potential clinical implications.
Journal Article
Piezo1 is required for outflow tract and aortic valve development
by
Faucherre, Adele
,
Hamid Moha Ou Maati
,
Avierinos, Jean Francois
in
Aortic valve
,
Blood flow
,
Coronary artery disease
2019
Aims: During embryogenesis, the onset of circulatory blood flow generates a variety of hemodynamic forces which reciprocally induce changes in cardiovascular development and performance. It has been known for some time that these forces can be detected by as yet unknown mechanosensory systems which in turn promote cardiogenic events such as outflow tract and aortic valve development. PIEZO1 is a mechanosensitive ion channel present in endothelial cells where it serves to detect hemodynamic forces making it an ideal candidate to play a role during cardiac development. We sought to determine whether PIEZO1 is required for outflow tract and aortic valve development. Methods and results: By analysing heart development in zebrafish we have determined that piezo1 is expressed in the developing outflow tract where it serves to detect hemodynamic forces. In particular, we have found that mechanical forces generated during the cardiac cycle activate Piezo1 which triggers nitric oxide to be released in the outflow tract. Consequently, disrupting Piezo1 signalling leads to defective outflow tract and aortic valve development and indicates this gene may be involved in the etiology of congenital heart diseases. Based on these findings, we analysed genomic data generated from a cohort of bicuspid aortic valve patients and identified 3 probands who each harboured a novel variant in PIEZO1. Subsequent in vitro and in vivo assays indicates that these variants behave as dominant negatives leading to an inhibition of normal PIEZO1 mechanosensory activity and defective aortic valve development. Conclusion: These data indicate that the mechanosensitive ion channel piezo1 is required for OFT and aortic valve development and, furthermore, dominant negative variants of PIEZO1 appear to be associated with BAV in humans.
Impact of an acute 1-month cannabidiol treatment on pain and inflammation after a long bone fracture: a triple-blind randomised, placebo-controlled, clinical trial protocol
by
Williamson, David
,
Arbour, Caroline
,
Deshaies, Amelie A
in
Acute Pain - drug therapy
,
Acute Pain - etiology
,
Adolescent
2025
IntroductionAcute pain levels following orthopaedic injury (eg, fracture) are a predictor of the onset of chronic pain, which affects nearly 50% of fracture patients and impairs functional recovery. Among current pharmacological treatments for acute pain, non-steroidal anti-inflammatory drugs have been associated with delayed bone healing, while opioids inhibit effective bone remodelling, increase the risk of pseudarthrosis and carry a high risk of addiction. In light of this, the development of new pain treatments is essential. Cannabidiol (CBD), a non-addictive and non-psychotropic cannabis component stands out as a potential therapeutic agent, given its analgesic and anti-inflammatory properties as well as its potential benefits for bone healing. This randomised controlled trial aims to investigate the effect of acute CBD treatment, compared with placebo, on patients’ self-reported pain, inflammation and well-being following a fracture injury.Methods and analysisThis is a triple-blind, randomised, placebo-controlled clinical trial. A total of 225 adults aged 18–70 years, who have suffered a long bone fracture and were treated at the Hôpital du Sacré-Coeur de Montréal, will be randomly assigned within 1 week to one of three treatment arms (25 mg or 50 mg of CBD or placebo) for 1 month. The primary outcome will be the difference in the pain score between groups at 1-month follow-up. Secondary outcomes will include measures of persistent pain, inflammation, opioid usage, quality of life, sleep quality, depression, anxiety, cognition and orthopaedic function. Data will be collected at baseline, 1-month and 3-month follow-ups.Ethics and disseminationThis study obtained a Health Canada licence for use of cannabis products. It has also been approved by Health Canada and the Research Ethics Board of the CIUSSS du Nord-de-l’Île-de-Montréal (Project ID 2025-2105). The findings will be published in a peer-reviewed journal and presented at local, national and international conferences. The trial’s results will be made publicly available on the ClinicalTrials.gov database.Trial registration number NCT06448923.
Journal Article