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result(s) for
"Chaib, Hassan"
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Longitudinal multi-omics of host–microbe dynamics in prediabetes
2019
Type 2 diabetes mellitus (T2D) is a growing health problem, but little is known about its early disease stages, its effects on biological processes or the transition to clinical T2D. To understand the earliest stages of T2D better, we obtained samples from 106 healthy individuals and individuals with prediabetes over approximately four years and performed deep profiling of transcriptomes, metabolomes, cytokines, and proteomes, as well as changes in the microbiome. This rich longitudinal data set revealed many insights: first, healthy profiles are distinct among individuals while displaying diverse patterns of intra- and/or inter-personal variability. Second, extensive host and microbial changes occur during respiratory viral infections and immunization, and immunization triggers potentially protective responses that are distinct from responses to respiratory viral infections. Moreover, during respiratory viral infections, insulin-resistant participants respond differently than insulin-sensitive participants. Third, global co-association analyses among the thousands of profiled molecules reveal specific host–microbe interactions that differ between insulin-resistant and insulin-sensitive individuals. Last, we identified early personal molecular signatures in one individual that preceded the onset of T2D, including the inflammation markers interleukin-1 receptor agonist (IL-1RA) and high-sensitivity C-reactive protein (CRP) paired with xenobiotic-induced immune signalling. Our study reveals insights into pathways and responses that differ between glucose-dysregulated and healthy individuals during health and disease and provides an open-access data resource to enable further research into healthy, prediabetic and T2D states.
Deep profiling of transcriptomes, metabolomes, cytokines, and proteomes, alongside changes in the microbiome, in samples from individuals with and without prediabetes reveal insights into inter-individual variability and associations between changes in the microbiome and other factors.
Journal Article
Filaggrin loss-of-function variants are associated with atopic dermatitis phenotypes in a diverse, early-life prospective cohort
2024
Loss-of-function (LoF) variants in the filaggrin (FLG) gene are the strongest known genetic risk factor for atopic dermatitis (AD), but the impact of these variants on AD outcomes is poorly understood. We comprehensively identified genetic variants through targeted region sequencing of FLG in children participating in the Mechanisms of Progression of Atopic Dermatitis to Asthma in Children cohort. Twenty FLG LoF variants were identified, including 1 novel variant and 9 variants not previously associated with AD. FLG LoF variants were found in the cohort. Among these children, the presence of 1 or more FLG LoF variants was associated with moderate/severe AD compared with those with mild AD. Children with FLG LoF variants had a higher SCORing for Atopic Dermatitis (SCORAD) and higher likelihood of food allergy within the first 2.5 years of life. LoF variants were associated with higher transepidermal water loss (TEWL) in both lesional and nonlesional skin. Collectively, our study identifies established and potentially novel AD-associated FLG LoF variants and associates FLG LoF variants with higher TEWL in lesional and nonlesional skin.
Journal Article
Identification of candidate cardiomyopathy modifier genes through genome sequencing and RNA profiling
by
Grove, Megan E.
,
Shang, Ching
,
Waggott, Daryl M.
in
Algorithms
,
Cardiomyopathy
,
Cardiovascular Medicine
2025
Phenotypic heterogeneity is apparent among individuals with putative monogenic disease, such as familial hypertrophic cardiomyopathy. Genome sequencing (GS) allows interrogation of the full spectrum of inborn genetic variation in an individual and RNA profiling provides a snapshot of the cardiac-specific pathogenic effects on gene expression.
Identify candidate genetic modifiers of hypertrophic cardiomyopathy phenotype.
We performed GS of 48 individuals with variants in
, the gene encoding beta myosin heavy chain, and a personal or family history of cardiomyopathy. The genome sequences were annotated with a custom pipeline optimized for cardiovascular gene variant detection. We utilized multiple lines of evidence to prioritize genes together with rare variant gene-based association testing to identify candidate genetic modifiers.
GS identified the
variant in all 48 cases. Several variants were reclassified based on best available data. We identified known disease-associated genes (
),
candidate modifiers (
,
and novel candidate modifiers of cardiomyopathy including
and
. We identified regulatory variants and intergenic regions associated with the phenotypes. Using RNA profiling, we show that several genes identified through gene-based association testing are differentially regulated in human hypertrophic cardiomyopathy, and in models of disease.
Evaluation of the whole genome, even in the case of alleged monogenic disease, leads to important new insights. The identified variants, regions, and genes are candidates to modify disease presentation in cardiomyopathy.
Journal Article
Studying Rare Movement Disorders: From Whole-Exome Sequencing to New Diagnostic and Therapeutic Approaches in a Modern Genetic Clinic
by
Perez-Maturo, Josefina
,
Bustamante, M. Leonor
,
Pauciulo, Michael
in
Ataxia
,
Basal ganglia
,
Central nervous system diseases
2024
Background: Rare movement disorders often have a genetic etiology. New technological advances have increased the odds of achieving genetic diagnoses: next-generation sequencing (NGS) (whole-exome sequencing—WES; whole-genome sequencing—WGS) and long-read sequencing (LRS). In 2017, we launched a WES program for patients with rare movement disorders of suspected genetic etiology. We aim to describe the accumulated experience of a modern movement disorder genetic clinic, highlighting how different available genetic tests might be prioritized according to the clinical phenotype and pattern of inheritance. Methods: Participants were studied through WES analysis. Descriptive statistics, including the mean, standard deviation, counts, and percentages, were used to summarize demographic and clinical characteristics in all subjects and with each type of result [pathogenic or likely pathogenic, variants of uncertain significance (VUS), negative]. Results: We studied 88 patients (93.2% Caucasian, 5.72% African American, and 1.08% Hispanic or Latino). After excluding six family members from four index participants, the diagnostic yield of WES reached 27% (22/82 probands). The age at onset was significantly lower in patients with pathogenic/likely pathogenic variants. The most common clinical phenotypes were ataxia and parkinsonism. Dystonia, ataxia, leukoencephalopathy, and parkinsonism were associated with most genetic diagnoses. Conclusions: We propose a comprehensive protocol with decision tree testing for WGS and LRS, a return of results, and a re-analysis of inconclusive genetic data to increase the diagnostic yield of patients with rare neurogenetic disorders.
Journal Article
Single-cell analyses define a continuum of cell state and composition changes in the malignant transformation of polyps to colorectal cancer
by
Laquindanum, Rozelle
,
Mills, Meredith
,
Becker, Winston R.
in
631/208/176
,
631/208/191
,
631/208/200
2022
To chart cell composition and cell state changes that occur during the transformation of healthy colon to precancerous adenomas to colorectal cancer (CRC), we generated single-cell chromatin accessibility profiles and single-cell transcriptomes from 1,000 to 10,000 cells per sample for 48 polyps, 27 normal tissues and 6 CRCs collected from patients with or without germline
APC
mutations. A large fraction of polyp and CRC cells exhibit a stem-like phenotype, and we define a continuum of epigenetic and transcriptional changes occurring in these stem-like cells as they progress from homeostasis to CRC. Advanced polyps contain increasing numbers of stem-like cells, regulatory T cells and a subtype of pre-cancer-associated fibroblasts. In the cancerous state, we observe T cell exhaustion, RUNX1-regulated cancer-associated fibroblasts and increasing accessibility associated with HNF4A motifs in epithelia. DNA methylation changes in sporadic CRC are strongly anti-correlated with accessibility changes along this continuum, further identifying regulatory markers for molecular staging of polyps.
Single-cell ATAC-seq and RNA-seq profiling traces the transformation of healthy colon to precancerous adenomas to colorectal cancer (CRC). A large proportion of polyp and CRC cells show a stem-like phenotype.
Journal Article
Electronic band structure and Shubnikov–de Haas effect in two-dimensional semimetallic InAs/GaSb nanostructure superlattice
by
Barkissy, Driss
,
El-Frikhe, Es-Said
,
Charifi, Hicham
in
Band structure of solids
,
Characterization and Evaluation of Materials
,
Condensed Matter Physics
2016
We have investigated the band structure
E
(
d
=
d
1
+
d
2
),
E
(
k
z
) and
E
(
k
p
), respectively, as a function of the SL period,
d
, in the growth direction and in plan of InAs(
d
1
= 160 Å)/GaSb(
d
2
= 105 Å) type II superlattice, performed in the envelope function formalism with the valence band offset,
Λ
, of 510 meV at 4.2 K. For the ratio
d
1
/
d
2
= 1.52,
d
and
Λ
dependence of the SL energy band gap show that the semiconductor-to-semimetal transition takes place at
d
c
= 173 Å and
Λ
c
= 463 meV. Therefore, this sample is semimetallic. The position of the Fermi level,
E
F
= 500.2 meV, indicates
n
type conductivity. The spectra of energy,
E
(
k
z
,
k
p
), show a negative band gap of −48.3 meV. The cutoff wavelength |
λ
c
| = 25.7 µm indicates that this sample can be used as a far-infrared detector. Further, we have interpreted the minima of the magnetoresistance oscillations, Shubnikov–de Haas effect, observed by D. M. Symons et al.
Journal Article
Multiomic analysis of familial adenomatous polyposis reveals molecular pathways associated with early tumorigenesis
2024
Familial adenomatous polyposis (FAP) is a genetic disease causing hundreds of premalignant polyps in affected persons and is an ideal model to study transitions of early precancer states to colorectal cancer (CRC). We performed deep multiomic profiling of 93 samples, including normal mucosa, benign polyps and dysplastic polyps, from six persons with FAP. Transcriptomic, proteomic, metabolomic and lipidomic analyses revealed a dynamic choreography of thousands of molecular and cellular events that occur during precancerous transitions toward cancer formation. These involve processes such as cell proliferation, immune response, metabolic alterations (including amino acids and lipids), hormones and extracellular matrix proteins. Interestingly, activation of the arachidonic acid pathway was found to occur early in hyperplasia; this pathway is targeted by aspirin and other nonsteroidal anti-inflammatory drugs, a preventative treatment under investigation in persons with FAP. Overall, our results reveal key genomic, cellular and molecular events during the earliest steps in CRC formation and potential mechanisms of pharmaceutical prophylaxis.
Snyder and colleagues present a comprehensive multiomic atlas of normal mucosal, benign polyps and dysplastic polyps from six persons with familial adenomatous polyposis, comprising transcriptomic, proteomic, metabolomic and lipidomic datasets.
Journal Article
Obesity Drives Delayed Infarct Expansion, Inflammation, and Distinct Gene Networks in a Mouse Stroke Model
by
Buckwalter, Marion S.
,
Lucas, Tawaun A.
,
Lechtenberg, Kendra J.
in
Animals
,
Biomedical and Life Sciences
,
Biomedicine
2021
Obesity is associated with chronic peripheral inflammation, is a risk factor for stroke, and causes increased infarct sizes. To characterize how obesity increases infarct size, we fed a high-fat diet to wild-type C57BL/6J mice for either 6 weeks or 15 weeks and then induced distal middle cerebral artery strokes. We found that infarct expansion happened late after stroke. There were no differences in cortical neuroinflammation (astrogliosis, microgliosis, or pro-inflammatory cytokines) either prior to or 10 h after stroke, and also no differences in stroke size at 10 h. However, by 3 days after stroke, animals fed a high-fat diet had a dramatic increase in microgliosis and astrogliosis that was associated with larger strokes and worsened functional recovery. RNA sequencing revealed a dramatic increase in inflammatory genes in the high-fat diet-fed animals 3 days after stroke that were not present prior to stroke. Genetic pathways unique to diet-induced obesity were primarily related to adaptive immunity, extracellular matrix components, cell migration, and vasculogenesis. The late appearance of neuroinflammation and infarct expansion indicates that there may be a therapeutic window between 10 and 36 h after stroke where inflammation and obesity-specific transcriptional programs could be targeted to improve outcomes in people with obesity and stroke.
Journal Article