Further characterization of Borjeson‐Forssman‐Lehmann syndrome in females due to de novo variants in PHF6

While inherited hemizygous variants in PHF6 cause X‐linked recessive Borjeson‐Forssman‐Lehmann syndrome (BFLS) in males, de novo heterozygous variants in females are associated with an overlapping but distinct phenotype, including moderate to severe intellectual disability, characteristic facial dysmorphism, dental, finger and toe anomalies, and linear skin pigmentation. By personal communication with colleagues, we assembled 11 additional females with BFLS due to variants in PHF6. We confirm the distinct phenotype to include variable intellectual disability, recognizable facial dysmorphism and other anomalies. We observed skewed X‐inactivation in blood and streaky skin pigmentation compatible with functional mosaicism. Variants occurred de novo in 10 individuals, of whom one was only mildly affected and transmitted it to her more severely affected daughter. The mutational spectrum comprises a two‐exon deletion, five truncating, one splice‐site and three missense variants, the latter all located in the PHD2 domain and predicted to severely destabilize the domain structure. This observation supports the hypothesis of more severe variants in females contributing to gender‐specific phenotypes in addition to or in combination with effects of X‐inactivation and functional mosaicism. Therefore, our findings further delineate the clinical and mutational spectrum of female BFLS and provide further insights into possible genotype–phenotype correlations between females and males.

Variants in SCAF4 Cause a Neurodevelopmental Disorder and Are Associated with Impaired mRNA Processing

RNA polymerase II interacts with various other complexes and factors to ensure correct initiation, elongation, and termination of mRNA transcription. One of these proteins is SR-related CTD-associated factor 4 (SCAF4), which is important for correct usage of polyA sites for mRNA termination. Using exome sequencing and international matchmaking, we identified nine likely pathogenic germline variants in SCAF4 including two splice-site and seven truncating variants, all residing in the N-terminal two thirds of the protein. Eight of these variants occurred de novo, and one was inherited. Affected individuals demonstrated a variable neurodevelopmental disorder characterized by mild intellectual disability, seizures, behavioral abnormalities, and various skeletal and structural anomalies. Paired-end RNA sequencing on blood lymphocytes of SCAF4-deficient individuals revealed a broad deregulation of more than 9,000 genes and significant differential splicing of more than 2,900 genes, indicating an important role of SCAF4 in mRNA processing. Knockdown of the SCAF4 ortholog CG4266 in the model organism Drosophila melanogaster resulted in impaired locomotor function, learning, and short-term memory. Furthermore, we observed an increased number of active zones in larval neuromuscular junctions, representing large glutamatergic synapses. These observations indicate a role of CG4266 in nervous system development and function and support the implication of SCAF4 in neurodevelopmental phenotypes. In summary, our data show that heterozygous, likely gene-disrupting variants in SCAF4 are causative for a variable neurodevelopmental disorder associated with impaired mRNA processing.

Genetic interaction screen for severe neurodevelopmental disorders reveals a functional link between Ube3a and Mef2 in Drosophila melanogaster

Neurodevelopmental disorders (NDDs) are clinically and genetically extremely heterogeneous with shared phenotypes often associated with genes from the same networks. Mutations in TCF4, MEF2C, UBE3A, ZEB2 or ATRX cause phenotypically overlapping, syndromic forms of NDDs with severe intellectual disability, epilepsy and microcephaly. To characterize potential functional links between these genes/proteins, we screened for genetic interactions in Drosophila melanogaster. We induced ubiquitous or tissue specific knockdown or overexpression of each single orthologous gene (Da, Mef2, Ube3a, Zfh1, XNP) and in pairwise combinations. Subsequently, we assessed parameters such as lethality, wing and eye morphology, neuromuscular junction morphology, bang sensitivity and climbing behaviour in comparison between single and pairwise dosage manipulations. We found most stringent evidence for genetic interaction between Ube3a and Mef2 as simultaneous dosage manipulation in different tissues including glia, wing and eye resulted in multiple phenotype modifications. We subsequently found evidence for physical interaction between UBE3A and MEF2C also in human cells. Systematic pairwise assessment of the Drosophila orthologues of five genes implicated in clinically overlapping, severe NDDs and subsequent confirmation in a human cell line revealed interactions between UBE3A/Ube3a and MEF2C/Mef2, thus contributing to the characterization of the underlying molecular commonalities.

Impact of Superparamagnetic Iron Oxide Nanoparticles on Vocal Fold Fibroblasts: Cell Behavior and Cellular Iron Kinetics

PURPOSE

The voice is the most important instrument of communication. Tissue defects in the vocal fold (VF) area lead to serious reduction in quality of life, but thus far, no satisfactory VF implant exists. Therefore, we aim to establish a functional VF implant in a rabbit model by magnetic tissue engineering (MTE) using superparamagnetic iron oxide nanoparticles (SPION). Hence, iron quantification over time as well as cell behavior studies upon SPION treatment are of great importance.

METHODS

Rabbit VF fibroblasts (VFF) were treated with different concentrations of SPIONs (20, 40, and 80 μg/cm²), and iron content was examined for up to 40 days using microwave plasma-atom emission spectroscopy. The effects of SPION treatment on VFF (adhesion, spreading, and migration), which are important for the formation of 3D structures, were tested.

RESULTS

Cellular SPION quantification revealed that there was no residual iron remaining in VFFs after 40 days. SPIONs had a dose-dependent effect on cell adhesion, with good tolerability observed up to 20 μg/cm². Migration and spreading were not significantly influenced by SPION treatment up to 80 μg/cm².

DISCUSSION AND CONCLUSION

To develop 3D structures, cell behavior should not be affected by SPION uptake. After 40 days, cells were free of iron as a result of metabolism or rarefication during cell division. Cell functions including adhesion, spreading, and migration were proven to be intact in a dose-dependent manner after SPION treatment, suggesting a safe usage of MTE for voice rehabilitation. Our results thus constitute a solid basis for a successful transfer of this technique into 3D constructs, in order to provide an individual and personalized human VF implant in the future.

Behaviour and ecotoxicology of aluminium in soil and water--review of the scientific literature

The scientific literature on chemical and biological behaviour of aluminium products and aluminium compounds following exposure to environmental media is considered. Although many studies have been performed on corrosion of aluminium products, no precise information exists about the amount of aluminium released by dissolution of the protective layer of aluminium products. Since no data are available on the effect caused by introduction of anthropogenic aluminium into the environment a comparison between aluminium released as a result of human activity and geogenic aluminium is only possible by estimating the extent to which anthropogenic aluminium is released using purely theoretical premises. The important results in the literature about the availability and toxicological effects of metallic aluminium and aluminium compounds are presented. Finally, a general assessment of the environmental compatibility of aluminium products is given.

Environmental hazard assessment of pharmaceuticals

The pharmaceuticals and pharmaceutical metabolites salicylic acid, paracetamol, clofibrinic acid, and methotrexate were examined with regard to their biological degradability and toxicity toward algae, Daphnia, fish embryos, luminescent bacteria, ciliates, and the fish cell line BF-2. The EC50 values calculated for the most sensitive organismic test (all except cell cultures) in each case were for salicylic acid, 37 mg/L (fish embryos); for paracetamol, 50 mg/L (Daphnia); for clofibrinic acid, 86 mg/L (fish embryos); and for methotrexate, 45 mg/L (ciliates). However, in the case of paracetamol, clofibrinic acid, and methotrexate, the fish cell line BF-2 reacted even more sensitively with EC50 values of 19 mg/L (paracetamol), 14 mg/L (clofibrinic acid), and 3 mg/L (methotrexate). Salicylic acid and paracetamol proved to be easily degradable. The predicted exposure concentration calculated according to the procedure of the EU Draft Phase I for new pharmaceuticals (CEC III/5504/94, draft 4) was based on the total estimated quantity of these substances consumed and indicated that their entry into the environment is theoretically possible. These results show that (1) the four tested pharmaceuticals may be present in the environment, (2) the substances led to effects in at least one ecotoxicological test, and (3) the most sensitive reactions were observed for a nonstandard test which incorporates relevant end points for the respective pharmaceuticals. This demonstrates that a limitation to the standard tests (algae, Daphnia, and fish) would have underestimated the toxicity of paracetamol, clofibrinic acid, and methotrexate. In addition to improved exposure estimates, the EU guideline should therefore contain a test strategy adapted to their modes of action, which permits the definite identification of pharmaceuticals with high ecotoxic potential, and consequently the appropriate provisions.

Effects of lindane on the planktonic community in freshwater microcosms

Effects of lindane on natural planktonic communities were investigated in aquatic indoor microcosms. Lindane was dosed to eight 300-liter microcosms for 2 weeks, and effects and recovery processes were monitored over 12 weeks. Mean measured water concentrations of lindane during the exposure period were 3, 6, 13, 27, 55, 102, 230, and 455 micrograms/liter. Zooplankton was severely affected by lindane. The most sensitive organisms were nauplii of copepodes which were affected at all treatment levels > or = 6 micrograms/liter during exposure (Days 2-14). Recovery of nauplii abundance was concentration-dependent at concentrations < or = 55 micrograms/liter lindane, whereas at concentrations > or = 102 micrograms/liter recovery was negligible. Cladocera abundance decreased during exposure to > or = 102 micrograms/liter lindane and did not recover to original levels until the end of the study. For phytoplankton, decreased population densities of Chlorophyceae and microalgae ( < 5 microns) were observed at lindane concentrations < or = 55 micrograms/liter, where zooplankton was only temporarily affected. At higher lindane, concentrations ( > or = 102 micrograms/liter) effects on phytoplankton were not clear, as also increases in abundances were observed, probably as a consequence of minimized grazing pressure, due to high zooplankton mortality. Comparison of these results with data obtained in complex outdoor systems demonstrates the practicability and sensitivity of indoor microcosms and emphasizes the importance of long-term testing and assessment of recovery processes for prediction of environmental effects.

Cytokine expression in T-cell lymphomas and Hodgkin's disease. Its possible implication in autocrine or paracrine production as a potential basis for neoplastic growth

The detection of an increasing number of cytokines and the demonstration of autocrine and paracrine mechanisms perpetuating tumor growth prompted the investigation of the expression of the cytokines IL-2, IL-3, IL-4, IL-5, IL-6, IFN gamma, Tac, and GMCSF in primary lymph-node biopsies of patients with peripheral T-cell lymphoma (n = 11), Hodgkin's disease (n = 13), and large-cell anaplastic lymphoma (n = 6) by means of Northern blot analysis and in situ hybridization (ISH); 15 of 28 cases had IL-6 message, predominantly in cases of Hodgkin's disease (HD) and large-cell anaplastic lymphomas (LCAL). Interferon gamma was found in about 50% of the cases among all entities. Other cytokine expression was rare except two cases of HD with high amounts of IL-4 mRNA. These results indicate that large amounts of growth factor transcripts are present in a variety of malignant lymphomas. The meaning of this expression is still unclear. It may be a loss of physiologic regulation within the cytokine network which may thus influence neoplastic cell growth as some cases have a quantity of cytokine expression which is similar or even above that of stimulated T cells. ISH demonstrates in individual cases that the expression is at least in part due to malignant cells.

Interleukin-9 expression in human malignant lymphomas: unique association with Hodgkin's disease and large cell anaplastic lymphoma

To test the possibility that interleukin-9 (IL-9), the human homologue of the mouse T-cell growth factor P40, may be involved in the pathogenesis of human lymphomas, we examined IL-9 expression in a variety of tumors both by Northern blot analysis and by in situ hybridization. Of 18 B-cell non-Hodgkin's lymphomas and 11 peripheral T-cell lymphomas, none expressed IL-9 message. By contrast, IL-9 message was found in two of six cases of large cell anaplastic lymphoma (LCAL) and in 6 of 13 cases of Hodgkin's disease (HD). In HD the strongest signals were observed in Hodgkin (H) and Sternberg-Reed (SR) cells, but IL-9 mRNA was also detected in small lymphocytic cells. A search for IL-9 message in a panel of 20 cell lines derived both from hematopoietic and nonhematopoietic tumors confirmed the unique association of IL-9 expression with HD and LCAL in as much as the only two cell lines with IL-9 message were derived from cases of HD and LCAL. These results suggest that IL-9 is not involved as an autocrine growth factor in the pathogenesis of most B- and T-cell lymphomas, but that it may play a role in HD and LCAL.

Cytokine expression in B-cell non-Hodgkin lymphomas

Cytokine expression of potentially active B-cell growth factors (IL-2, IL-4, IL-6) was investigated by means of mRNA-expression in 29 cases of malignant non-Hodgkin B-cell lymphomas. Strong signals were found for IL-4 and IL-6 in two and five cases, respectively, whereas the majority of the remaining cases did not show any detectable mRNA-signals for these growth factors. Comparing these results with those of the immunohistochemistry, it could be demonstrated that at least in some of these cases the signal was due to an autocrine or paracrine phenomenon of the tumour cells.

Induction of antigen expression of follicular dendritic cells in a monoblastic cell line. A contribution to its cellular origin

Experiments were carried out to elucidate the cellular origin of the dendritic reticulum cell (DRC). The monoblastic cell line THP-1, the histiocytic cell line U-937, and the mononuclear cell fraction from peripheral blood (PMC) were stimulated with supernatants from lectin-stimulated peripheral blood lymphocytes and from stimulated T- and B-cell lines. Differentiation towards DRC was assessed by immunocytochemical demonstration of the DRC-specific antigen Ki-M4. Supernatants from isolated peripheral T lymphocytes and from T- and B-cell lines were capable of stimulating THP-1 to Ki-M4 antigen expression, whereas U-937 and the PMC fraction remained negative for this antigen throughout the experiments. These results provide further evidence for a relationship of DRCs with the mononuclear-phagocytic cell system and hence for their bone marrow origin. Furthermore, the data suggest that soluble factors of T and/or B cells are involved in mediating the differentiation process of precursor cells to DRC.