675 research outputs found

    Pathogenic NR2F1 variants cause a developmental ocular phenotype recapitulated in a mutant mouse model

    Get PDF
    Pathogenic NR2F1 variants cause a rare autosomal dominant neurodevelopmental disorder referred to as the Bosch-Boonstra-Schaaf Optic Atrophy Syndrome. Although visual loss is a prominent feature seen in affected individuals, the molecular and cellular mechanisms contributing to visual impairment are still poorly characterized. We conducted a deep phenotyping study on a cohort of 22 individuals carrying pathogenic NR2F1 variants to document the neurodevelopmental and ophthalmological manifestations, in particular the structural and functional changes within the retina and the optic nerve, which have not been detailed previously. The visual impairment became apparent in early childhood with small and/or tilted hypoplastic optic nerves observed in 10 cases. High-resolution optical coherence tomography imaging confirmed significant loss of retinal ganglion cells with thinning of the ganglion cell layer, consistent with electrophysiological evidence of retinal ganglion cells dysfunction. Interestingly, for those individuals with available longitudinal ophthalmological data, there was no significant deterioration in visual function during the period of follow-up. Diffusion tensor imaging tractography studies showed defective connections and disorganization of the extracortical visual pathways. To further investigate how pathogenic NR2F1 variants impact on retinal and optic nerve development, we took advantage of an Nr2f1 mutant mouse disease model. Abnormal retinogenesis in early stages of development was observed in Nr2f1 mutant mice with decreased retinal ganglion cell density and disruption of retinal ganglion cell axonal guidance from the neural retina into the optic stalk, accounting for the development of optic nerve hypoplasia. The mutant mice showed significantly reduced visual acuity based on electrophysiological parameters with marked conduction delay and decreased amplitude of the recordings in the superficial layers of the visual cortex. The clinical observations in our study cohort, supported by the mouse data, suggest an early neurodevelopmental origin for the retinal and optic nerve head defects caused by NR2F1 pathogenic variants, resulting in congenital vision loss that seems to be non-progressive. We propose NR2F1 as a major gene that orchestrates early retinal and optic nerve head development, playing a key role in the maturation of the visual system

    Overexpression of the Axl tyrosine kinase receptor in cutaneous SCC-derived cell lines and tumours

    Get PDF
    The molecular mechanisms that underlie the development of squamous cell skin cancers (SSC) are poorly understood. We have used oligonucleotide microarrays to compare the differences in cellular gene expression between a series of keratinocyte cell that mimic disease progression with the aim of identifying genes that may potentially contribute towards squamous cell carcinoma (SCC) progression in vivo, and in particular to identify markers that may serve as potential therapeutic targets for SCC treatment. Gene expression differences were corroborated by polymerase chain reaction and Western blotting. We identified Axl, a receptor tyrosine kinase with transforming potential that has also been shown to have a role in cell survival, adhesion and chemotaxis, was upregulated in vitro in SCC-derived cells compared to premalignant cells. Extending the investigation to tumour biopsies showed that the Axl protein was overexpressed in vivo in a series of SCCs

    New herbal bitter liqueur with high antioxidant activity and lower sugar content: innovative approach to liqueurs formulations

    Get PDF
    Herbal liqueurs are spirits with numerous functional properties, due to the presence of bioactive extractable compounds deriving from herbs. The aim of this study was to obtain new herbal bitter liqueur (HBL) on the basis of twelve selected bitter and aromatic plants extracts, with an optimal sensory profile for consumer acceptance. Also, the determination of optimal sugar content in HBL was done. Furthermore, antioxidant (AO) capacity and total phenolic content (TPC) of HBL was evaluated and compared to similar commercial herbal spirits. Among five tested formulations, assessed by 9-point hedonic scale, HBL with the ratio of bitter and aromatic plants 1:4 was the most acceptable. Ideal concentration of sugar in HBL, determined using a just-about-right scale, was found to be 80.32 g/l of sucrose, which is approximately 20% less than the minimum stipulated by European Union Regulation and several times lower than in the majority of commercial liqueurs. Obtained result indicates the possibility of sugar reduction in liqueurs, and suggests the need to carry out sensory analysis before production of these high-calorie beverages. Radical scavenging ability against DPPH and ABTS radicals, as well as ferric reducing antioxidant power and TPC of HBL were convincingly superior in comparison to similar commercial herbal alcoholic beverages. High correlation coefficients between TPC and other assays applied strongly support the significant role of the polyphenols in the total AO capacity of the HBL and other tested commercial herbal spirits. Headspace GC/MS revealed that the most abundant terpenes were menthone (3.75%), eucalyptol (3.42%) and menthol (3.10%), whereas methanol was present in a small amount (4.97 mg/l)

    Chromosome 20p11.2 deletions cause congenital hyperinsulinism via the loss of FOXA2 or its regulatory elements

    Get PDF
    This is the final version. Available on open access from Springer Nature via the DOI in this recordData availability: All non-clinical data analyzed during this study are included in this article (and its Supplementary Information). The 20p11.2 variants reported in this study were uploaded to ClinVar (SUB14235415). Clinical and genotype data can be used to identify individuals and are therefore available only through collaboration to experienced teams working on approved studies examining the mechanisms, cause, diagnosis and treatment of diabetes and other beta cell disorders. Requests for collaboration will be considered by a steering committee following an application to the Genetic Beta Cell Research Bank (https://www.diabetesgenes.org/current-research/genetic-beta-cell-research-bank/). Contact by email should be directed to S. Flanagan ([email protected]). All requests for access to data will be responded to within 14 d. Accession codes and DOI numbers for all ChIP-seq, ATAC-seq, RNA-seq and scRNA-seq datasets are provided in Supplementary Table 2. We used the Genome Reference Consortium Human Build 37 (GRCh37) to annotate genetic data (accession number GCF_000001405.13). Details of this assembly are provided at https://www.ncbi.nlm.nih.gov/assembly/GCF_000001405.13/.Persistent congenital hyperinsulinism (HI) is a rare genetically heterogeneous condition characterised by dysregulated insulin secretion leading to life-threatening hypoglycaemia. For up to 50% of affected individuals screening of the known HI genes does not identify a disease-causing variant. Large deletions have previously been used to identify novel regulatory regions causing HI. Here, we used genome sequencing to search for novel large (>1 Mb) deletions in 180 probands with HI of unknown cause and replicated our findings in a large cohort of 883 genetically unsolved individuals with HI using off-target copy number variant calling from targeted gene panels. We identified overlapping heterozygous deletions in five individuals (range 3-8 Mb) spanning chromosome 20p11.2. The pancreatic beta-cell transcription factor gene, FOXA2, a known cause of HI was deleted in two of the five individuals. In the remaining three, we found a minimal deleted region of 2.4 Mb adjacent to FOXA2 that encompasses multiple non-coding regulatory elements that are in conformational contact with FOXA2. Our data suggests that the deletions in these three children may cause disease through the dysregulation of FOXA2 expression. These findings provide new insights into the regulation of FOXA2 in the beta-cell and confirm an aetiological role for chromosome 20p11.2 deletions in syndromic HI.Wellcome Trus

    Gefitinib Induces Epidermal Growth Factor Receptor Dimers Which Alters the Interaction Characteristics with 125I-EGF

    Get PDF
    The tyrosine kinase inhibitor gefitinib inhibits growth in some tumor types by targeting the epidermal growth factor receptor (EGFR). Previous studies show that the affinity of the EGF-EGFR interaction varies between hosting cell line, and that gefitinib increases the affinity for some cell lines. In this paper, we investigate possible mechanisms behind these observations. Real-time interaction analysis in LigandTracer® Grey revealed that the HER2 dimerization preventing antibody pertuzumab clearly modified the binding of 125I-EGF to EGFR on HER2 overexpressing SKOV3 cells in the presence of gefitinib. Pertuzumab did not affect the binding on A431 cells, which express low levels of HER2. Cross-linking measurements showed that gefitinib increased the amount of EGFR dimers 3.0–3.8 times in A431 cells in the absence of EGF. In EGF stimulated SKOV3 cells the amount of EGFR dimers increased 1.8–2.2 times by gefitinib, but this effect was cancelled by pertuzumab. Gefitinib treatment did not alter the number of EGFR or HER2 expressed in tumor cell lines A431, U343, SKOV3 and SKBR3. Real-time binding traces were further analyzed in a novel tool, Interaction Map, which deciphered the different components of the measured interaction and supports EGF binding to multiple binding sites. EGFR and HER2 expression affect the levels of EGFR monomers, homodimers and heterodimers and EGF binds to the various monomeric/dimeric forms of EGFR with unique binding properties. Taken together, we conclude that dimerization explains the varying affinity of EGF – EGFR in different cells, and we propose that gefitinib induces EGFR dimmers, which alters the interaction characteristics with 125I-EGF

    High level expression of differentially localized BAG-1 isoforms in some oestrogen receptor-positive human breast cancers

    Get PDF
    Sensitivity to oestrogens and apoptosis are critical determinants of the development and progression of breast cancer and reflect closely linked pathways in breast epithelial cells. For example, induction of BCL-2 oncoprotein expression by oestrogen contributes to suppression of apoptosis and BCL-2 and oestrogen receptor (ER) are frequently co-expressed in tumours. BAG-1/HAP is a multifunctional protein which complexes with BCL-2 and steroid hormone receptors (including the ER), and can suppress apoptosis and influence steroid hormone-dependent transcription. Therefore, analysis of expression of BAG-1 in human breast cancer is of considerable interest. BAG-1 was readily detected by immunostaining in normal breast epithelial cells and most ER-positive tumours, but was undetectable or weakly expressed in ER-negative tumours. BAG-1 positive cells showed a predominantly cytoplasmic or cytoplasmic plus nuclear distribution of staining. A correlation between ER and BAG-1 was also evident in breast cancer derived cell lines, as all lines examined with functional ER expression also expressed high levels of BAG-1. In addition to the prototypical 36 kDa BAG-1 isoform, breast cancer cells expressed higher molecular weight isoforms and, in contrast to BCL-2, BAG-1 expression was independent of oestrogens. BAG-1 isoforms were differentially localized to the nucleus or cytoplasm and this was also independent of oestrogens. These results demonstrate a close association between BAG-1 and functional ER expression and suggest BAG-1 may be useful as a therapeutic target or prognostic marker in breast cancer. © 1999 Cancer Research Campaig

    Additive growth inhibitory effects of ibandronate and antiestrogens in estrogen receptor-positive breast cancer cell lines

    Get PDF
    INTRODUCTION: Bisphosphonates are inhibitors of osteoclast-mediated tumor-stimulated osteolysis, and they have become standard therapy for the management of bone metastases from breast cancer. These drugs can also directly induce growth inhibition and apoptosis of osteotropic cancer cells, including estrogen receptor-positive (ER+) breast cancer cells. METHODS: We examined the anti-proliferative properties of ibandronate on two ER+ breast cancer cell lines (MCF-7 and IBEP-2), and on one ER negative (ER-) cell line (MDA-MB-231). Experiments were performed in steroid-free medium to assess ER regulation and the effect of ibandronate in combination with estrogen or antiestrogens. RESULTS: Ibandronate inhibited cancer cell growth in a dose- and time-dependent manner (approximate IC(50): 10(-4 )M for MCF-7 and IBEP-2 cells; 3 × 10(-4 )M for MDA-MB-231 cells), partly through apoptosis induction. It completely abolished the mitogenic effect induced by 17β-estradiol in ER+ breast cancer cells, but affected neither ER regulation nor estrogen-induced progesterone receptor expression, as documented in MCF-7 cells. Moreover, ibandronate enhanced the growth inhibitory action of partial (4-hydroxytamoxifen) and pure (ICI 182,780, now called fluvestrant or Faslodex™) antiestrogens in estrogen-sensitive breast cancer cells. Combination analysis identified additive interactions between ibandronate and ER antagonists. CONCLUSION: These data constitute the first in vitro evidence for additive effects between ibandronate and antiestrogens, supporting their combined use for the treatment of bone metastases from breast cancer
    corecore