A comparative study of aluminium and nutrient concentrations in mistletoes on aluminium‐accumulating and non‐accumulating hosts

Mistletoes offer a unique model to study interactions among Al and nutrients in vascular plants, because they grow and reproduce on hosts with distinct Al uptake strategies. We investigated Al distribution and nutrient relations of mistletoes on Al‐accumulating and non‐accumulating hosts. We hypothesised that mistletoes would exhibit similar leaf nutrient and Al concentrations as their host plants, but a strong compartmentalisation of Al when growing on Al‐accumulators. We measured concentrations of N, P, K, Ca, Mg, Cu, Fe, Mn, Zn in leaves and Al in leaves, seeds and branches of Phthirusa ovata and Psittacanthus robustus infecting Miconia albicans, an Al‐accumulator, and Ph. ovata infecting Byrsonima verbascifolia, a non‐Al‐accumulator. High leaf concentrations of Al in Ph. ovata only occurred while parasitizing the Al‐accumulating host; there was no accumulation in branches or seeds. In P. robustus, large concentrations of Al were found in leaves, branches and seeds. Mistletoe seed viability and leaf nutrient concentrations were not affected by Al accumulation. Passive uptake of Al, Ca, Mg, Mn and Cu in mistletoes was evidenced by significant correlations between mistletoes and host leaf concentrations, but not of N, P and K. Al was retranslocated to different plant organs in P. robustus, whereas it was mostly restricted to leaves in Ph. ovata. We suggest that Al might have some specific function in P. robustus, which only parasitizes Al‐accumulator hosts, while the host generalist Ph. ovata can be considered a facultative Al‐accumulator.     

Fetal mesenchymal stromal cells from cryopreserved human chorionic villi: cytogenetic and molecular analysis of genome stability in long-term cultures

Background aimsFirst-trimester chorionic villi (CV) are an attractive source of human mesenchymal stromal cells (hMSC) for possible applications in cellular therapy and regenerative medicine. Human MSC from CV were monitored for genetic stability in long-term cultures.MethodsWe set up a good manufacturing practice cryopreservation procedure for small amounts of native CV samples. After isolation, hMSC were in vitro cultured and analyzed for biological end points. Genome stability at different passages of expansion was explored by karyotype, genome-wide array-comparative genomic hybridization and microsatellite genotyping.ResultsGrowth curve analysis revealed a high proliferative potential of CV-derived cells. Immunophenotyping showed expression of typical MSC markers and absence of hematopoietic markers. Analysis of multilineage potential demonstrated efficient differentiation into adipocytes, osteocytes, chondrocytes and induction of neuro-glial commitment. In angiogenic experiments, differentiation in endothelial cells was detected by in vitro Matrigel assay after vascular endothelial growth factor stimulation. Data obtained from karyotyping, array-comparative genomic hybridization and microsatellite genotyping comparing early with late DNA passages did not show any genomic variation at least up to passage 10. Aneuploid clones appeared in four of 14 cases at latest passages, immediately before culture growth arrest.ConclusionsOur findings indicate that hCV-MSC are genetically stable in long-term cultures at least up to passage 10 and that it is possible to achieve clinically relevant amounts of hCV-MSC even after few stages of expansion. Genome abnormalities at higher passages can occasionally occur and are always associated with spontaneous growth arrest. Under these circumstances, hCV-MSC could be suitable for therapeutic purposes.     

Oxidative Stress and Erythrocyte Membrane Alterations in Children with Autism: Correlation with Clinical Features

It has been suggested that oxidative stress may play a role in the pathogenesis of Autism Spectrum Disorders (ASD), but the literature reports somewhat contradictory results. To further investigate the issue, we evaluated a high number of peripheral oxidative stress parameters, and some related issues such as erythrocyte membrane functional features and lipid composition. Twenty-one autistic children (Au) aged 5 to 12 years, were gender and age-matched with 20 typically developing children (TD). Erythrocyte thiobarbituric acid reactive substances, urinary isoprostane and hexanoyl-lysine adduct levels were elevated in Au, thus confirming the occurrence of an imbalance of the redox status of Au, whilst other oxidative stress markers or associated parameters (urinary 8-oxo-dG, plasma radical absorbance capacity and carbonyl groups, erythrocyte superoxide dismutase and catalase activities) were unchanged. A very significant reduction of Na⁺/K⁺-ATPase activity (−66%, p<0.0001), a reduction of erythrocyte membrane fluidity and alteration in erythrocyte fatty acid membrane profile (increase in monounsaturated fatty acids, decrease in EPA and DHA-ω3 with a consequent increase in ω6/ω3 ratio) were found in Au compared to TD, without change in membrane sialic acid content. Some Au clinical features appear to be correlated with these findings; in particular, hyperactivity score appears to be related with some parameters of the lipidomic profile and membrane fluidity. Oxidative stress and erythrocyte membrane alterations may play a role in the pathogenesis of ASD and prompt the development of palliative therapeutic protocols. Moreover, the marked decrease in NKA could be potentially utilized as a peripheral biomarker of ASD.     

The Cannabinoid Receptor Type 2 as Mediator of Mesenchymal Stromal Cell Immunosuppressive Properties

Mesenchymal stromal cells are non-hematopoietic, multipotent progenitor cells producing cytokines, chemokines, and extracellular matrix proteins that support hematopoietic stem cell survival and engraftment, influence immune effector cell development, maturation, and function, and inhibit alloreactive T-cell responses. The immunosuppressive properties of human mesenchymal stromal cells have attracted much attention from immunologists, stem cell biologists and clinicians.Recently, the presence of the endocannabinoid system in hematopoietic and neural stem cells has been demonstrated. Endocannabinoids, mainly acting through the cannabinoid receptor subtype 2, are able to modulate cytokine release and to act as immunosuppressant when added to activated T lymphocytes.In the present study, we have investigated, through a multidisciplinary approach, the involvement of the endocannabinoids in migration, viability and cytokine release of human mesenchymal stromal cells.We show, for the first time, that cultures of human mesenchymal stromal cells express all of the components of the endocannabinoid system, suggesting a potential role for the cannabinoid CB2 receptor as a mediator of anti-inflammatory properties of human mesenchymal stromal cells, as well as of their survival pathways and their capability to home and migrate towards endocannabinoid sources.     

Molecular Typing of Lung Adenocarcinoma on Cytological Samples Using a Multigene Next Generation Sequencing Panel

Identification of driver mutations in lung adenocarcinoma has led to development of targeted agents that are already approved for clinical use or are in clinical trials. Therefore, the number of biomarkers that will be needed to assess is expected to rapidly increase. This calls for the implementation of methods probing the mutational status of multiple genes for inoperable cases, for which limited cytological or bioptic material is available. Cytology specimens from 38 lung adenocarcinomas were subjected to the simultaneous assessment of 504 mutational hotspots of 22 lung cancer-associated genes using 10 nanograms of DNA and Ion Torrent PGM next-generation sequencing. Thirty-six cases were successfully sequenced (95%). In 24/36 cases (67%) at least one mutated gene was observed, including EGFR, KRAS, PIK3CA, BRAF, TP53, PTEN, MET, SMAD4, FGFR3, STK11, MAP2K1. EGFR and KRAS mutations, respectively found in 6/36 (16%) and 10/36 (28%) cases, were mutually exclusive. Nine samples (25%) showed concurrent alterations in different genes. The next-generation sequencing test used is superior to current standard methodologies, as it interrogates multiple genes and requires limited amounts of DNA. Its applicability to routine cytology samples might allow a significant increase in the fraction of lung cancer patients eligible for personalized therapy.     

P-I Snake Venom Metalloproteinase Is Able to Activate the Complement System by Direct Cleavage of Central Components of the Cascade

Background

Snake Venom Metalloproteinases (SVMPs) are amongst the key enzymes that contribute to the high toxicity of snake venom. We have recently shown that snake venoms from the Bothrops genus activate the Complement system (C) by promoting direct cleavage of C-components and generating anaphylatoxins, thereby contributing to the pathology and spread of the venom. The aim of the present study was to isolate and characterize the C-activating protease from Bothrops pirajai venom.

Results

Using two gel-filtration chromatography steps, a metalloproteinase of 23 kDa that activates Complement was isolated from Bothrops pirajai venom. The mass spectrometric identification of this protein, named here as C-SVMP, revealed peptides that matched sequences from the P-I class of SVMPs. C-SVMP activated the alternative, classical and lectin C-pathways by cleaving the α-chain of C3, C4 and C5, thereby generating anaphylatoxins C3a, C4a and C5a. In vivo, C-SVMP induced consumption of murine complement components, most likely by activation of the pathways and/or by direct cleavage of C3, leading to a reduction of serum lytic activity.

Conclusion

We show here that a P-I metalloproteinase from Bothrops pirajai snake venom activated the Complement system by direct cleavage of the central C-components, i.e., C3, C4 and C5, thereby generating biologically active fragments, such as anaphylatoxins, and by cleaving the C1-Inhibitor, which may affect Complement activation control. These results suggest that direct complement activation by SVMPs may play a role in the progression of symptoms that follow envenomation.