98 research outputs found
Human Placental Arterial Distensibility, Birth Weight, and Body Size Are Positively Related to Fetal Homocysteine Concentration
Methionine demethylation during metabolism generates homocysteine (Hcy) and its remethylation requires
folate and cobalamin. Elevated Hcy concentrations are associated with vascular-related complications of
pregnancy, including increased vascular stiffness, predictive of clinical vascular disease. Maternal and fetal
total Hcy (tHcy) concentrations are positively related, yet the influence of Hcy on fetoplacental vascular
function in normal pregnancy has not been examined. We hypothesized that Hcy alters fetoplacental vascular
characteristics with influences on fetal growth outcomes. We investigated (1) placental chorionic plate
artery distensibility and neonatal blood pressure in relation to umbilical plasma tHcy; (2) relationships between
cord venous (CV) and cord arterial (CA) plasma tHcy, folate, and cobalamin concentrations; and (3) tHcy
associations with birth weight and anthropometric measurements of body size as indices of fetal growth
in normal pregnancies with appropriate weight-for-gestational age newborns. Maternal plasma tHcy,
folate, and cobalamin concentrations were consistent with published data. Placental chorionic plate artery
distensibility index (ÎČ; measure of vessel stiffness) was inversely related to CA tHcy, yet neonatal blood pressure
was not significantly affected. CV and CA tHcy concentrations were positively related and CV tHcy
negatively related to CV cobalamin but not folate. CV tHcy concentration positively related to birth
weight, corrected birth weight per-centile, length, head circumference, and mid-arm circumference of
newborns. CV cobalamin was inversely related to fetal growth indices but not to folate concentration. Our
study demonstrates a potential relationship between fetal tHcy and placental artery distensibility, placing
clinical relevance to cobalamin in influencing Hcy concentration and maintaining low vascular resistance to
facilitate nutrient exchange favorable to fetal growth
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 âgain-of-functionâ 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 âhot-spotâ 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 âhot-spotâ 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
Lower urinary tract and bowel dysfunction in spinocerebellar ataxias
Background: Little information is available in spinocerebellar ataxias (SCAs)
regarding pelvic organ symptoms. The aim of this study was to characterize the
lower urinary tract (LUT) and bowel dysfunction in autosomal dominant
spinocerebellar ataxias. Methods: Patients with confirmed SCAs attending a tertiary care service were approached about LUT and bowel complaints, and completed validated questionnaires: urinary symptom profile (USP), QualiveenShort form, International Prostate Symptom Score, and Neurogenic Bowel Dysfunction Score. SCA3 and SCA7 patients with urological complaints additionally underwent urodynamic studies (UDS). Patientsâ characterization included
demographic, clinical (Scale for the Assessment and Rating of Ataxia (SARA),
Inventory of Non-Ataxia Signs (INAS)), and genetic variables. Descriptive and
comparative analyses were performed. Results: Fifty-one patients participated:
SCA1 (n = 4), SCA2 (n = 11), SCA3 (n = 13), SCA6 (n = 17), and SCA7
(n = 6). The prevalence of self-reported LUT symptoms was 60.8% (n = 31),
whereas LUT symptoms was reported in 86.3%(n = 44) using the USP. Both
storage and voiding symptoms were reported, urinary frequency and urgency
being the most frequent (n = 34, 68%). Although LUT symptoms were most
often classed as mild (n = 27, 61.4%), they impacted QoL in 38 patients
(77.6%). Of these, 21 (55.3%) were not on pharmacological treatment for urinary dysfunction. Most common abnormalities in UDS (n = 14) were detrusor
overactivity (storage phase) and detrusor underactivity (voiding phase). Bowel
symptoms were less common (31.4%, n = 16) and of mild severity. Conclusion: LUT symptoms are prevalent in SCA patients and impact QoL, whereas
bowel symptoms tend to be mild. These symptoms are overlooked by patients
and physicians due to the complexity of neurological involvement in SCA, and
therefore a multidisciplinary management approach should be adopted
Validation of RNA Extraction Methods and Suitable Reference Genes for Gene Expression Studies in Developing Fetal Human Inner Ear Tissue
\ua9 2024 by the authors.A comprehensive gene expression investigation requires high-quality RNA extraction, in sufficient amounts for real-time quantitative polymerase chain reaction and next-generation sequencing. In this work, we compared different RNA extraction methods and evaluated different reference genes for gene expression studies in the fetal human inner ear. We compared the RNA extracted from formalin-fixed paraffin-embedded tissue with fresh tissue stored at â80 \ub0C in RNAlater solution and validated the expression stability of 12 reference genes (from gestational week 11 to 19). The RNA from fresh tissue in RNAlater resulted in higher amounts and a better quality of RNA than that from the paraffin-embedded tissue. The reference gene evaluation exhibited four stably expressed reference genes (B2M, HPRT1, GAPDH and GUSB). The selected reference genes were then used to examine the effect on the expression outcome of target genes (OTOF and TECTA), which are known to be regulated during inner ear development. The selected reference genes displayed no differences in the expression profile of OTOF and TECTA, which was confirmed by immunostaining. The results underline the importance of the choice of the RNA extraction method and reference genes used in gene expression studies
Leukocyte telomere length variability as a potential biomarker in patients with polyQ diseases
SCA1, SCA2, and SCA3 are the most common forms of SCAs among the polyglutamine disorders, which include Huntington's Disease (HD). We investigated the relationship between leukocyte telomere length (LTL) and the phenotype of SCA1, SCA2, and SCA3, comparing them with HD. The results showed that LTL was significantly reduced in SCA1 and SCA3 patients, while LTL was significantly longer in SCA2 patients. A significant negative relationship between LTL and age was observed in SCA1 but not in SCA2 subjects. LTL of SCA3 patients depend on both patient's age and disease duration. The number of CAG repeats did not affect LTL in the three SCAs. Since LTL is considered an indirect marker of an inflammatory response and oxidative damage, our data suggest that in SCA1 inflammation is present already at an early stage of disease similar to in HD, while in SCA3 inflammation and impaired antioxidative processes are associated with disease progression. Interestingly, in SCA2, contrary to SCA1 and SCA3, the length of leukocyte telomeres does not reduce with age. We have observed that SCAs and HD show a differing behavior in LTL for each subtype, which could constitute relevant biomarkers if confirmed in larger cohorts and longitudinal studies
Widespread dynamic and pleiotropic expression of the melanocortin-1-receptor (MC1R) system is conserved across chick, mouse and human embryonic development
Background
MC1R, a Gâprotein coupled receptor with high affinity for alphaâmelanocyte stimulating hormone (αMSH), modulates pigment production in melanocytes from many species and is associated with human melanoma risk. MC1R mutations affecting human skin and hair color also have pleiotropic effects on the immune response and analgesia. Variants affecting human pigmentation in utero alter the congenital phenotype of both oculocutaneous albinism and congenital melanocytic naevi, and have a possible effect on birthweight.
Methods and Results
By in situ hybridization, RTâPCR and immunohistochemistry, we show that MC1R is widely expressed during human, chick and mouse embryonic and fetal stages in many somatic tissues, particularly in the musculoskeletal and nervous systems, and conserved across evolution in these three amniotes. Its dynamic pattern differs from that of TUBB3, a gene overlapping the same locus in humans and encoding class III ÎČâtubulin. The αMSH peptide and the transcript for its precursor, proâopiomelanocortin (POMC), are similarly present in numerous extraâcutaneous tissues. MC1R genotyping of variants p.(V60M) and p.(R151C) was undertaken for 867 healthy children from the Avon Longitudinal Study of Parent and Children (ALSPAC) cohort, and birthweight modeled using multiple logistic regression analysis. A significant positive association initially found between R151C and birth weight, independent of known birth weight modifiers, was not reproduced when combined with data from an independent genomeâwide association study of 6,459 additional members of the same cohort.
Conclusions
These data clearly show a new and hitherto unsuspected role for MC1R in noncutaneous solid tissues before birth
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 âgain-of-functionâ 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 âhot-spotâ 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 âhot-spotâ 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
Amiloride, fluoxetine or riluzole to reduce brain volume loss in secondary progressive multiple sclerosis: the MS-SMART four-arm RCT
Background:
Neuroprotective drugs are needed to slow or prevent neurodegeneration and disability accrual in secondary progressive multiple sclerosis. Amiloride, fluoxetine and riluzole are repurposed drugs with potential neuroprotective effects.
Objectives:
To assess whether or not amiloride, fluoxetine and riluzole can reduce the rate of brain volume loss in people with secondary progressive multiple sclerosis over 96 weeks. The secondary objectives that were assessed were feasibility of a multiarm trial design approach, evaluation of anti-inflammatory effects, clinician- and patient-reported efficacy and three mechanistic substudies.
Design:
A multicentre, multiarm, randomised, double-blind, placebo-controlled, parallel-group Phase IIb trial with follow-up at 4, 8, 12, 24, 36, 48, 72 and 96 weeks. Patients, investigators (including magnetic resonance imaging analysts), and treating and independent assessing neurologists were blinded to the treatment allocation. The target sample size was 440 patients.
Setting:
Thirteen UK clinical neuroscience centres.
Participants:
Participants were aged 25â65 years, had secondary progressive multiple sclerosis with evidence of disease progression independent of relapses in the previous 2 years, and had an Expanded Disability Status Scale score of 4.0â6.5. Patients were ineligible if they could not have a magnetic resonance imaging scan; had a relapse or steroids in the previous 3 months; or had epilepsy, depression, bipolar disorder, glaucoma, bleeding disorders or significant organ comorbidities. Exclusion criteria were concurrent disease-modified treatments, immunosuppressants or selective serotonin reuptake inhibitors.
Interventions:
Participants received amiloride (5âmg), fluoxetine (20âmg), riluzole (50âmg) or placebo (randomised 1â:â1â:â1â:â1) twice daily.
Main outcome measures:
The primary end point was magnetic resonance imaging-derived percentage brain volume change at 96 weeks. Secondary end points were new/enlarging T2 lesions, pseudoatrophy, and clinician- and patient-reported measures (including the Expanded Disability Status Scale, Multiple Sclerosis Functional Composite, Symbol Digit Modalities Test, low-contrast letter visual acuity, Multiple Sclerosis Impact Scale 29 items, version 2, Multiple Sclerosis Walking Scale, version 2, and questionnaires addressing pain and fatigue). The exploratory end points included measures of persistent new T1 hypointensities and grey matter volume changes. The substudies were advanced magnetic resonance imaging, optical coherence tomography and cerebrospinal fluid analyses.
Results:
Between December 2014 and June 2016, 445 patients were randomised (analysed) to amiloride [nâ=â111 (99)], fluoxetine [nâ=â111 (96)], riluzole [nâ=â111 (99)] or placebo [nâ=â112 (99)]. A total of 206 randomised patients consented to the advanced magnetic resonance imaging substudy, 260 consented to the optical coherence tomography substudy and 70 consented to the cerebrospinal fluid substudy. No significant difference was seen between the active drugs and placebo in percentage brain volume change at week 96 as follows (where negative values mean more atrophy than placebo): amiloride minus placebo 0.0% (Dunnett-adjusted 95% confidence interval â0.4% to 0.5%), fluoxetine minus placebo â0.1% (Dunnett-adjusted 95% confidence interval â0.5% to 0.3%); riluzole minus placebo â0.1% (Dunnett-adjusted 95% confidence interval â0.6% to 0.3%). There was good adherence to study drugs. The proportion of patients experiencing adverse events was similar in the treatment and placebo groups. There were no emergent safety issues.
Limitations:
There was a lower than expected uptake in the cerebrospinal fluid substudy.
Conclusions:
A multiarm Phase II paradigm is efficient in determining which neuroprotective agents to take through to Phase III trials. Amiloride, fluoxetine and riluzole were not effective in reducing the brain atrophy rate in people with secondary progressive multiple sclerosis. Mechanistic pathobiological insight was gained.
Future work:
To use the information gained from the Multiple Sclerosis-Secondary Progressive Multi-Arm Randomisation Trial (MS-SMART) to inform future trial design as new candidate agents are identified.
Trial registration:
Current Controlled Trials ISRCTN28440672, NCT01910259 and EudraCT 2012-005394-31.
Funding:
This project was funded by the Efficacy and Mechanism Evaluation (EME) programme, a Medical Research Council and National Institute for Health Research (NIHR) partnership. This will be published in full in Efficacy and Mechanism Evaluation; Vol. 7, No. 3. See the NIHR Journals Library website for further project information. This trial also received funding from the UK MS Society and the US National Multiple Sclerosis Society
Author Correction: Enhanced NF-ÎșB signaling in type-2 dendritic cells at baseline predicts non-response to adalimumab in psoriasis.
Funder: Department of HealthBiologic therapies have transformed the management of psoriasis, but clinical outcome is variable leaving an unmet clinical need for predictive biomarkers of response. Here we perform in-depth immunomonitoring of blood immune cells of 67 patients with psoriasis, before and during therapy with the anti-TNF drug adalimumab, to identify immune mediators of clinical response and evaluate their predictive value. Enhanced NF-ÎșBp65 phosphorylation, induced by TNF and LPS in type-2 dendritic cells (DC) before therapy, significantly correlates with lack of clinical response after 12 weeks of treatment. The heightened NF-ÎșB activation is linked to increased DC maturation in vitro and frequency of IL-17+ T cells in the blood of non-responders before therapy. Moreover, lesional skin of non-responders contains higher numbers of dermal DC expressing the maturation marker CD83 and producing IL-23, and increased numbers of IL-17+ T cells. Finally, we identify and clinically validate LPS-induced NF-ÎșBp65 phosphorylation before therapy as a predictive biomarker of non-response to adalimumab, with 100% sensitivity and 90.1% specificity in an independent cohort. Our study uncovers important molecular and cellular mediators underpinning adalimumab mechanisms of action in psoriasis and we propose a blood biomarker for predicting clinical outcome
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