44 research outputs found

    Air-stable photoconductive films formed from perylene bisimide gelators

    Get PDF
    We show that amino acid-PBIs can form one-dimensional structures at high pH and then gels at low pH. Both the dried solutions and dried gels are photoconductive. Interestingly, photoconductivity of these materials requires that the incident light has a wavelength shorter than 400 nm, in stark contrast with the absorption maxima of the PBIs. The photoconductivity correlates with the formation of the perylene radical anion, which is unusually highly stable in air for many hours

    Bi-allelic pathogenic variants in HS2ST1 cause a syndrome characterized by developmental delay and corpus callosum, skeletal and renal abnormalities

    Get PDF
    Heparan sulfate belongs to the group of glycosaminoglycans (GAGs), highly sulphated linear polysaccharides. Heparan sulfate 2-O-sulfotransferase 1 (HS2ST1) is one of several specialized enzymes required for heparan sulfate synthesis and catalyzes the transfer of the sulfate groups to the sugar moiety of heparan sulfate. We report biallelic pathogenic variants in the HS2ST1 gene in four individuals from three unrelated families. Affected individuals showed facial dysmorphism with coarse face, upslanted palpebral fissures, broad nasal tip, and wide mouth, developmental delay and/or intellectual disability, corpus callosum agenesis or hypoplasia, flexion contractures, brachydactyly of hands and feet with broad fingertips and toes, and uni- or bilateral renal agenesis in three individuals. HS2ST1 variants cause a reduction in HS2ST1 mRNA and decreased or absent heparan sulfate 2-O-sulfotransferase 1 in two of three fibroblast cell lines derived from affected individuals. The heparan sulfate synthesized by the individual 1 cell line lacks 2-O-sulfated domains but had an increase in N- and 6-O-sulfated domains demonstrating functional impairment of the HS2ST1. As heparan sulfate modulates FGF-mediated signaling, we found a significantly decreased activation of the MAP kinases ERK1/2 in FGF-2-stimulated cell lines of affected individuals that could be restored by addition of heparin, a GAG similar to heparan sulfate. Focal adhesions in FGF-2-stimulated fibroblasts of affected individuals showed an increased length and concentrated at the cell periphery. Our data demonstrate that a heparan sulfate synthesis deficit causes a novel recognizable syndrome and emphasize a role for 2-O-sulfated heparan sulfate in human neuronal, skeletal and renal development

    Expanding the phenotype of the X-linked BCOR microphthalmia syndromes

    Get PDF
    Two distinct syndromes arise from pathogenic variants in the X-linked gene BCOR (BCL-6 corepressor): oculofaciocardiodental (OFCD) syndrome, which affects females, and a severe microphthalmia (‘Lenz’-type) syndrome affecting males. OFCD is an X-linked dominant syndrome caused by a variety of BCOR null mutations. As it manifests only in females, it is presumed to be lethal in males. The severe male X-linked recessive microphthalmia syndrome (‘Lenz’) usually includes developmental delay in addition to the eye findings and is caused by hypomorphic BCOR variants, mainly by a specific missense variant c.254C > T, p.(Pro85Leu). Here, we detail 16 new cases (11 females with 4 additional, genetically confirmed, affected female relatives; 5 male cases each with unaffected carrier mothers). We describe new variants and broaden the phenotypic description for OFCD to include neuropathy, muscle hypotonia, pituitary underdevelopment, brain atrophy, lipoma and the first description of childhood lymphoma in an OFCD case. Our male X-linked recessive cases show significant new phenotypes: developmental delay (without eye anomalies) in two affected half-brothers with a novel BCOR variant, and one male with high myopia, megalophthalmos, posterior embryotoxon, developmental delay, and heart and bony anomalies with a previously undescribed BCOR splice site variant. Our female OFCD cases and their affected female relatives showed variable features, but consistently had early onset cataracts. We show that a mosaic carrier mother manifested early cataract and dental anomalies. All female carriers of the male X-linked recessive cases for whom genetic confirmation was available showed skewed X-inactivation and were unaffected. In view of the extended phenotype, we suggest a new term of X-linked BCOR-related syndrome

    5q11.2 deletion syndrome revisited—Further narrowing of the smallest region of overlap for the main clinical characteristics of the syndrome

    No full text
    Microdeletions at 5q11.2 are rare. Subjects show a phenotypic spectrum that overlaps CHARGE syndrome and 22q11.2 deletion syndrome. A growing number of subjects present with learning difficulty and/or intellectual disability, immune deficiency, congenital heart malformation, and dysmorphism. DHX29 and IL6ST have been proposed as candidate genes for the development of the major clinical manifestations. We present a new case and narrow down the shortest region of overlap to evaluate possible candidate genes. Our case does not present developmental delay or immune deficiency indicating a reduced penetrance for some of the main clinical manifestations. The shortest region of overlap between subjects with deletions at 5q11.2 is approximately 450 kb (position 54.3–54.7 Mb). The narrowed region comprises 10 protein coding genes, including DHX29. DHX29 is a strong candidate gene for the main features of 5q11.2-microdeletion syndrome; however, our findings suggest a joined impact of several genes as the cause of the syndrome

    IL-1 receptor type 1 gene-deficient mice demonstrate an impaired host defense against pneumococcal meningitis

    No full text
    The fatality rate associated with Streptococcus pneumoniae meningitis remains high despite adequate antibiotic treatment. IL-1 is an important proinflammatory cytokine, which is up-regulated in brain tissue after the induction of meningitis. To determine the role of IL-1 in pneumococcal meningitis we induced meningitis by intranasal inoculation with 8x10(4) CFU of S. pneumoniae and 180 U of hyaluronidase in IL-1R type I gene-deficient (IL-IR-/-) mice and wild-type mice. Meningitis resulted in elevated IL-1alpha and IL-1beta mRNA and protein levels in the brain. The absence of an intact IL-1 signal was associated with a higher susceptibility to develop meningitis. Furthermore, the lack of IL-1 impaired bacterial clearance, as reflected by an increased number of CFU in cerebrospinal fluid of IL-1R(-/-) mice. The characteristic pleocytosis of meningitis was not significantly altered in IL-1R(-/-) mice,, but meningitis was associated with lower brain levels of cytokines. The mortality was significantly higher and earlier in the course of the disease in IL-1R(-/-) mice. These results demonstrate that endogenous IL-1 is required for an adequate host defense in pneumococcal meningiti
    corecore