645 research outputs found
Analysis of CDKN1C in fetal growth restriction and pregnancy loss [version 2; peer review: 2 approved]
Background: Cyclin-dependent kinase inhibitor 1C (CDKN1C) is a key
negative regulator of cell growth encoded by a paternally
imprinted/maternally expressed gene in humans. Loss-of-function
variants in CDKN1C are associated with an overgrowth condition
(Beckwith-Wiedemann Syndrome) whereas “gain-of-function” variants
in CDKN1C that increase protein stability cause growth restriction as
part of IMAGe syndrome ( Intrauterine growth restriction, M
etaphyseal dysplasia, Adrenal hypoplasia and Genital anomalies). As
three families have been reported with CDKN1C mutations who have
fetal growth restriction (FGR)/Silver-Russell syndrome (SRS) without
adrenal insufficiency, we investigated whether pathogenic variants in
CDKN1C could be associated with isolated growth restriction or
recurrent loss of pregnancy.
Methods: Analysis of published literature was undertaken to review
the localisation of variants in CDKN1C associated with IMAGe
syndrome or fetal growth restriction. CDKN1C expression in different
tissues was analysed in available RNA-Seq data (Human Protein Atlas).
Targeted sequencing was used to investigate the critical region of
CDKN1C for potential pathogenic variants in SRS (n=66), FGR (n=37),
DNA from spontaneous loss of pregnancy (n= 22) and women with
recurrent miscarriages (n=78) (total n=203).
Results: All published single nucleotide variants associated with
IMAGe syndrome are located in a highly-conserved “hot-spot” within
the PCNA-binding domain of CDKN1C between codons 272-279.
Variants associated with familial growth restriction but normal
adrenal function currently affect codons 279 and 281. CDKN1C is
highly expressed in the placenta compared to adult tissues, which
may contribute to the FGR phenotype and supports a role in
pregnancy maintenance. In the patient cohorts studied no pathogenic
variants were identified in the PCNA-binding domain of CDKN1C.
Conclusion: CDKN1C is a key negative regulator of growth. Variants in
a very localised “hot-spot” cause growth restriction, with or without
adrenal insufficiency. However, pathogenic variants in this region are
not a common cause of isolated fetal growth restriction phenotypes
or loss-of-pregnancy/recurrent miscarriages
A genomic atlas of human adrenal and gonad development [version 1; referees: awaiting peer review]
Background: In humans, the adrenal glands and gonads undergo distinct biological events between 6-10 weeks post conception (wpc), such as testis determination, the onset of steroidogenesis and primordial germ cell development. However, relatively little is currently known about the genetic mechanisms underlying these processes. We therefore aimed to generate a detailed genomic atlas of adrenal and gonad development across these critical stages of human embryonic and fetal development. / Methods: RNA was extracted from 53 tissue samples between 6-10 wpc (adrenal, testis, ovary and control). Affymetrix array analysis was performed and differential gene expression was analysed using Bioconductor. A mathematical model was constructed to investigate time-series changes across the dataset. Pathway analysis was performed using ClueGo and cellular localisation of novel factors confirmed using immunohistochemistry. / Results: Using this approach, we have identified novel components of adrenal development (e.g. ASB4, NPR3) and confirmed the role of SRY as the main human testis-determining gene. By mathematical modelling time-series data we have found new genes up-regulated with SOX9 in the testis (e.g. CITED1), which may represent components of the testis development pathway. We have shown that testicular steroidogenesis has a distinct onset at around 8 wpc and identified potential novel components in adrenal and testicular steroidogenesis (e.g. MGARP, FOXO4, MAP3K15, GRAMD1B, RMND2), as well as testis biomarkers (e.g. SCUBE1). We have also shown that the developing human ovary expresses distinct subsets of genes (e.g. OR10G9, OR4D5), but enrichment for established biological pathways is limited. / Conclusion: This genomic atlas is revealing important novel aspects of human development and new candidate genes for adrenal and reproductive disorders
A genomic atlas of human adrenal and gonad development [version 2; referees: 4 approved]
BACKGROUND: In humans, the adrenal glands and gonads undergo distinct
biological events between 6-10 weeks post conception (wpc), such as testis
determination, the onset of steroidogenesis and primordial germ cell
development. However, relatively little is currently known about the genetic
mechanisms underlying these processes. We therefore aimed to generate a
detailed genomic atlas of adrenal and gonad development across these critical
stages of human embryonic and fetal development.
METHODS: RNA was extracted from 53 tissue samples between 6-10 wpc
(adrenal, testis, ovary and control). Affymetrix array analysis was performed
and differential gene expression was analysed using Bioconductor. A
mathematical model was constructed to investigate time-series changes across
the dataset. Pathway analysis was performed using ClueGo and cellular
localisation of novel factors confirmed using immunohistochemistry.
RESULTS: Using this approach, we have identified novel components of adrenal
development (e.g. ASB4, NPR3) and confirmed the role of SRY as the main
human testis-determining gene. By mathematical modelling time-series data
we have found new genes up-regulated with SOX9 in the testis (e.g. CITED1),
which may represent components of the testis development pathway. We have
shown that testicular steroidogenesis has a distinct onset at around 8 wpc and
identified potential novel components in adrenal and testicular steroidogenesis
(e.g. MGARP, FOXO4, MAP3K15, GRAMD1B, RMND2), as well as testis
biomarkers (e.g. SCUBE1). We have also shown that the developing human
ovary expresses distinct subsets of genes (e.g. OR10G9, OR4D5), but
enrichment for established biological pathways is limited.
CONCLUSION: This genomic atlas is revealing important novel aspects of human
development and new candidate genes for adrenal and reproductive disorders
Next generation sequencing reveals novel genetic variants (SRY, DMRT1, NR5A1, DHH, DHX37) in adults with 46,XY DSD
Context: The genetic basis of human sex development is slowly being elucidated and more than 40 different genetic causes of differences (or disorders) of sex development (DSD) have now been reported. However, reaching a specific diagnosis using traditional approaches can be difficult, especially in adults where limited biochemical data may be available. /
Objective: We used a targeted next-generation sequencing approach to analyze known and candidate genes for DSD in individuals with no specific molecular diagnosis. /
Partcipants and Design: We studied 52 adult 46,XY women attending a single-center adult service, who were part of a larger cohort of 400 individuals. Classic conditions such as17β-hydroxysteroid dehydrogenase deficiency type 3, 5α-reductase deficiency type 2 and androgen insensitivity syndrome were excluded. The study cohort had broad working diagnoses of complete gonadal dysgenesis (CGD) (n=27) and partially-virilised 46,XY DSD (pvDSD) (n=25), a group that included partial gonadal dysgenesis (PGD) and those with a broad ”partial androgen insensitivity syndrome” label. Targetted sequencing of 168 genes was undertaken. /
Results: Overall a likely genetic cause was found in 16/52 (30.8%) individuals (22.2% CGD; 40.0% pvDSD). Pathogenic variants were found in SRY (n=3), DMRT1 (n=1), NR5A1/SF-1 (n=1) and DHH (n=1) in the CGD group, and in NR5A1 (n=5), DHH (n=1) and DHX37 (n=4) in the pvDSD group. /
Conclusions: Reaching a specific diagnosis can have clinical implications and provides insight into the role of these proteins in sex development. Next-generation sequencing approaches are invaluable, especially in adult populations or where diagnostic biochemistry is not possible
Analysis of CDKN1C in fetal growth restriction and pregnancy loss
Background: Cyclin-dependent kinase inhibitor 1C (CDKN1C) is a key negative regulator of cell growth encoded by a paternally imprinted/maternally expressed gene in humans. Loss-of-function variants in CDKN1C are associated with an overgrowth condition (Beckwith-Wiedemann Syndrome) whereas “gain-of-function” variants in CDKN1C that increase protein stability cause growth restriction as part of IMAGe syndrome (Intrauterine growth restriction, Metaphyseal dysplasia, Adrenal hypoplasia and Genital anomalies). As two families have been reported with CDKN1C mutations who have fetal growth restriction (FGR)/Silver-Russell syndrome (SRS) without adrenal insufficiency, we investigated whether pathogenic variants in CDKN1C could be associated with isolated growth restriction or recurrent loss of pregnancy. //
Methods: Analysis of published literature was undertaken to review the localisation of variants in CDKN1C associated with IMAGe syndrome or fetal growth restriction. CDKN1C expression in different tissues was analysed in available RNA-Seq data (Human Protein Atlas). Targeted sequencing was used to investigate the critical region of CDKN1C for potential pathogenic variants in SRS (n=58), FGR (n=26), DNA from spontaneous loss of pregnancy (n= 21) and women with recurrent miscarriages (n=71) (total n=176). // Results: All published single nucleotide variants associated with IMAGe syndrome are located in a highly-conserved “hot-spot” within the PCNA-binding domain of CDKN1C between codons 272-279. Variants associated with familial growth restriction but normal adrenal function currently affect codons 279 and 281. CDKN1C is highly expressed in the placenta compared to adult tissues, which may contribute to the FGR phenotype and supports a role in pregnancy maintenance. In the patient cohorts studied no pathogenic variants were identified in the PCNA-binding domain of CDKN1C. //
Conclusion: CDKN1C is a key negative regulator of growth. Variants in a very localised “hot-spot” cause growth restriction, with or without adrenal insufficiency. However, pathogenic variants in this region are not a common cause of isolated fetal growth restriction phenotypes or loss-of-pregnancy/recurrent miscarriages
Frequency-resolved Monte Carlo
We adapt the Quantum Monte Carlo method to the cascaded formalism of quantum optics, allowing us to simulate the emission of photons of known energy. Statistical processing of the photon clicks thus collected agrees with the theory of frequency-resolved photon correlations, extending the range of applications based on correlations of photons of prescribed energy, in particular those of a photon-counting character. We apply the technique to autocorrelations of photon streams from a two-level system under coherent and incoherent pumping, including the Mollow triplet regime where we demonstrate the direct manifestation of leapfrog processes in producing an increased rate of two-photon emission events
Angiosarcoma of the nasal cavity: a case report
Angiosarcomas are malignant neoplasias of rapid growth that develop from endothelial cells. They represent 2% of all sarcomas and only 1–4% are located in the aerodigestive tract. Since 1977, only 16 cases have been reported
The CBI-R detects early behavioural impairment in genetic frontotemporal dementia
Introduction: Behavioural dysfunction is a key feature of genetic frontotemporal dementia (FTD) but validated clinical scales measuring behaviour are lacking at present. Methods: We assessed behaviour using the revised version of the Cambridge Behavioural Inventory (CBI-R) in 733 participants from the Genetic FTD Initiative study: 466 mutation carriers (195 C9orf72, 76 MAPT, 195 GRN) and 267 non-mutation carriers (controls). All mutation carriers were stratified according to their global CDR plus NACC FTLD score into three groups: asymptomatic (CDR = 0), prodromal (CDR = 0.5) and symptomatic (CDR = 1+). Mixed-effects models adjusted for age, education, sex and family clustering were used to compare between the groups. Neuroanatomical correlates of the individual domains were assessed within each genetic group. Results: CBI-R total scores were significantly higher in all CDR 1+ mutation carrier groups compared with controls [C9orf72 mean 70.5 (standard deviation 27.8), GRN 56.2 (33.5), MAPT 62.1 (36.9)] as well as their respective CDR 0.5 groups [C9orf72 13.5 (14.4), GRN 13.3 (13.5), MAPT 9.4 (10.4)] and CDR 0 groups [C9orf72 6.0 (7.9), GRN 3.6 (6.0), MAPT 8.5 (13.3)]. The C9orf72 and GRN 0.5 groups scored significantly higher than the controls. The greatest impairment was seen in the Motivation domain for the C9orf72 and GRN symptomatic groups, whilst in the symptomatic MAPTgroup, the highest-scoring domains were Stereotypic and Motor Behaviours and Memory and Orientation. Neural correlates of each CBI-R domain largely overlapped across the different mutation carrier groups. Conclusions: The CBI-R detects early behavioural change in genetic FTD, suggesting that it could be a useful measure within future clinical trials
The Soluble Recombinant Neisseria meningitidis Adhesin NadAΔ351–405 Stimulates Human Monocytes by Binding to Extracellular Hsp90
The adhesin NadA favors cell adhesion/invasion by hypervirulent Neisseria meningitidis B (MenB). Its recombinant form NadAΔ351–405, devoid of the outer membrane domain, is an immunogenic candidate for an anti-MenB vaccine able to stimulate monocytes, macrophages and dendritic cells. In this study we investigated the molecular mechanism of NadAΔ351–405 cellular effects in monocytes. We show that NadAΔ351–405 (against which we obtained polyclonal antibodies in rabbits), binds to hsp90, but not to other extracellular homologous heat shock proteins grp94 and hsp70, in vitro and on the surface of monocytes, in a temperature dependent way. Pre-incubation of monocytes with the MenB soluble adhesin interfered with the binding of anti-hsp90 and anti-hsp70 antibodies to hsp90 and hsp70 at 37°C, a condition in which specific cell-binding occurs, but not at 0°C, a condition in which specific cell-binding is very diminished. Conversely, pre-incubation of monocytes with anti-hsp90 and anti-hsp70 antibodies did not affected NadAΔ351–405 cell binding in any temperature condition, indicating that it associates to another receptor on their plasma membrane and then laterally diffuses to encounter hsp90. Consistently, polymixin B interfered with NadAΔ351–405 /hsp90 association, abrogated the decrease of anti-hsp90 antibodies binding to the cell surface due to NadAΔ351–405 and inhibited adhesin-induced cytokine/chemokine secretion without affecting monocyte-adhesin binding. Co-stimulation of monocytes with anti-hsp90 antibodies and NadAΔ351–405 determined a stronger but polymixin B insensitive cell activation. This indicated that the formation of a recombinant NadA/hsp90/hsp70 complex, although essential for full monocyte stimulation, can be replaced by anti-hsp90 antibody/hsp90 binding. Finally, the activation of monocytes by NadAΔ351–405 alone or in the presence of anti-hsp90 antibodies were both inhibited by neutralizing anti-TLR4 antibodies, but not by anti-TLR2 antibodies. We propose that hsp90-dependent recruitment into an hsp90/hsp70/TLR4 transducing signal complex is necessary for the immune-stimulating activity of NadAΔ351–405 anti-MenB vaccine candidate
Erratic Flu Vaccination Emerges from Short-Sighted Behavior in Contact Networks
The effectiveness of seasonal influenza vaccination programs depends on individual-level compliance. Perceptions about risks associated with infection and vaccination can strongly influence vaccination decisions and thus the ultimate course of an epidemic. Here we investigate the interplay between contact patterns, influenza-related behavior, and disease dynamics by incorporating game theory into network models. When individuals make decisions based on past epidemics, we find that individuals with many contacts vaccinate, whereas individuals with few contacts do not. However, the threshold number of contacts above which to vaccinate is highly dependent on the overall network structure of the population and has the potential to oscillate more wildly than has been observed empirically. When we increase the number of prior seasons that individuals recall when making vaccination decisions, behavior and thus disease dynamics become less variable. For some networks, we also find that higher flu transmission rates may, counterintuitively, lead to lower (vaccine-mediated) disease prevalence. Our work demonstrates that rich and complex dynamics can result from the interaction between infectious diseases, human contact patterns, and behavior
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