Synchrotron X-ray Fluorescence Microscopy unveils selenium distribution and a phloem-sink hypothesis in Neptunia amplexicaulis.

Neptunia amplexicaulis is a legume that grows on seleniferous soils in Queensland, Australia. It is one of the strongest known selenium (Se) hyperaccumulators, capable of accumulating up to 13,600 μg Se g-1 in its leaves. This study aimed to investigate the distribution and translocation of Se within N.

X-ray fluorescence microscopy and X-ray absorption spectroscopy reveal the stability of the plecstatin-1 scaffold in biological model systems: comparison of Ru, Os and Ir analogues.

Plecstatin-1 ([RuCl(-cym)(pca)]Cl; -cym = -cymene, pca = (4-fluorophenyl-2-pyridinecarbothioamide)) is an organometallic anticancer compound of the ruthenium "piano-stool"/"half-sandwich" class which displays promising pre-clinical results. Its mode of action is ascribed to targeting plectin in the cytoskeleton to inhibit cancer cell motility. In this research, we report X-ray fluorescence microscopy (XFM) data demonstrating that the cellular distributions of the metals from the Os and Ir analogues of plecstatin-1 are identical to that of Ru in SKOV-3 ovarian cancer cells treated with plecstatin-1.

Selenium Distribution and Speciation in Tissues from Rats Administered with Non-Native Selenotrisulfides.

Selenotrisulfides (STS, R-S-Se-S-R) are metabolic intermediates in the bioconversion of inorganic Se species to organoselenium compounds. These Se species are reactive with a variety of endogenous molecules, particularly thiol-containing proteins, with this reactivity facilitating Se transport and subsequent utilization within the body. In this study, X-ray fluorescence microscopy (XFM) and high energy resolution fluorescence detected X-ray absorption spectroscopy (HERFD-XAS) were applied to investigate Se distribution and speciation in vivo.

Somatic cell count as an indicator of subclinical mastitis and increased inflammatory response in asymptomatic lactating women.

Unlabelled: Subclinical mastitis is an asymptomatic inflammatory condition that can be difficult to define and diagnose. In the dairy industry, subclinical mastitis is diagnosed by milk somatic cell counts (SCCs) of ≥250,000 cells mL. In this pilot study, we assessed the efficacy of this index to identify human subclinical mastitis by comparing SCC levels with the inflammatory response [interleukin-8 (IL-8) levels] in 37 samples from asymptomatic and 10 clinical mastitis (CM) lactating women.

Expression levels of the selenium-uptake receptor LRP8, the antioxidant selenoprotein GPX1 and steroidogenic enzymes correlate in granulosa cells.

Abstract: Reactive oxygen species (ROS) are a by-product of the activity of cytochrome P450 steroidogenic enzymes. Antioxidant enzymes protect against ROS damage. To identify if any particular antioxidant enzyme is used to protect against ROS produced by granulosa cells as follicles enlarge and produce oestradiol, we measured in the bovine granulosa cells the expression of two steroidogenic enzymes (CYP11A1, CYP19A1), important for progesterone and oestradiol production.

Correlative multimodal optical and X-ray fluorescence imaging of brominated fluorophores.

Imaging with multiple modalities can maximise the information gained from the analysis of a single sample. probes for optical fluorescence and X-ray fluorescence microscopy based on brominated 4-amino-1,8-naphthalimide and BODIPY scaffolds have been successfully designed and synthesised. Herein we show that these prototype probes, based on each of these scaffolds, can be imaged in two different cancer cell lines, and that the respective optical fluorescence and X-ray fluorescence signals are well correlated in these images.

The gut virome is associated with stress-induced changes in behaviour and immune responses in mice.

The microbiota-gut-brain axis has been shown to play an important role in the stress response, but previous work has focused primarily on the role of the bacteriome. The gut virome constitutes a major portion of the microbiome, with bacteriophages having the potential to remodel bacteriome structure and activity. Here we use a mouse model of chronic social stress, and employ 16S rRNA and whole metagenomic sequencing on faecal pellets to determine how the virome is modulated by and contributes to the effects of stress.

Mechanisms of Uptake and Translocation of Thallium in Vegetables: An X-ray Fluorescence Microspectroscopic Investigation.

Most nonoccupational human exposure to thallium (Tl) occurs via consumption of contaminated food crops. cultivars are common crops that can accumulate more than 500 μg Tl g. Knowledge of Tl uptake and translocation mechanisms in cultivars is fundamental to developing methods to inhibit Tl uptake or conversely for potential use in phytoremediation of polluted soils.

Histatin-5 interacts with cellular copper to promote antifungal activity against Candida albicans.

Histatin-5 (Hist-5) is an antimicrobial peptide found in human saliva that functions to defend the oral cavity from microbial infections, such as those caused by the fungal pathogen Candida albicans (C. albicans). Hist-5 can bind Cu in multiple oxidation states, Cu2+ and Cu+in vitro, and supplemental Cu2+ has been shown to improve the fungicidal activity of the peptide against C.

Towards multimodal cellular imaging: optical and X-ray fluorescence.

Imaging techniques permit the study of the molecular interactions that underlie health and disease. Each imaging technique collects unique chemical information about the cellular environment. Multimodal imaging, using a single probe that can be detected by multiple imaging modalities, can maximise the information extracted from a single cellular sample by combining the results of different imaging techniques.

Optimizing Arsenic Therapy by Selectively Targeting Leukemia Cells.

Arsenic, in the simple form of arsenic trioxide, is currently marketed for the treatment of acute promyelocytic leukemia. Due to the multifaceted mechanisms of action of arsenic, it has also shown promise in other types of leukemias but is hindered by its toxic effects toward normal cells. This research has aimed to determine whether tumor-homing peptide complexes of arsenic can be designed and developed to strategically target specific cancers.

Chemical transformations of arsenic in the rhizosphere-root interface of Pityrogramma calomelanos and Pteris vittata.

Pityrogramma calomelanos and Pteris vittata are cosmopolitan fern species that are the strongest known arsenic (As) hyperaccumulators, with potential to be used in the remediation of arsenic-contaminated mine tailings. However, it is currently unknown what chemical processes lead to uptake of As in the roots. This information is critical to identify As-contaminated soils that can be phytoremediated, or to improve the phytoremediation process.

Alzheimer's Drug PBT2 Interacts with the Amyloid β 1-42 Peptide Differently than Other 8-Hydroxyquinoline Chelating Drugs.

Although Alzheimer's disease (AD) was first described over a century ago, it remains the leading cause of age-related dementia. Innumerable changes have been linked to the pathology of AD; however, there remains much discord regarding which might be the initial cause of the disease. The "amyloid cascade hypothesis" proposes that the amyloid β (Aβ) peptide is central to disease pathology, which is supported by elevated Aβ levels in the brain before the development of symptoms and correlations of amyloid burden with cognitive impairment.

Multimodal synchrotron X-ray fluorescence imaging reveals elemental distribution in seeds and seedlings of the Zn-Cd-Ni hyperaccumulator Noccaea caerulescens.

The molecular biology and genetics of the Ni-Cd-Zn hyperaccumulator Noccaea caerulescens has been extensively studied, but no information is yet available on Ni and Zn redistribution and mobilization during seed germination. Due to the different physiological functions of these elements, and their associated transporter pathways, we expected differential tissue distribution and different modes of translocation of Ni and Zn during germination. This study used synchrotron X-ray fluorescence tomography techniques as well as planar elemental X-ray imaging to elucidate elemental (re)distribution at various stages of the germination process in contrasting accessions of N.

Cellular-level distribution of manganese in Macadamia integrifolia, M. ternifolia, and M. tetraphylla from Australia.

Macadamia integrifolia and M. tetraphylla, unlike M. ternifolia, are known for their edible nuts.

Contrasting patterns of nickel distribution in the hyperaccumulators Phyllanthus balgooyi and Phyllanthus rufuschaneyi from Malaysian Borneo.

Globally, the majority of Ni hyperaccumulator plants occur on ultramafic soils in tropical regions, and the genus Phyllanthus, from the Phyllanthaceae family, is globally the most represented taxonomical group. Two species from Sabah (Malaysia) are remarkable because Phyllanthus balgooyi can attain >16 wt% of Ni in its phloem exudate, while Phyllanthus rufuschaneyi reaches foliar concentrations of up to 3.5 wt% Ni, which are amongst the most extreme concentrations of Ni in any plant tissue.

Impact of Food Origin Strains on the Human Intestinal Microbiota in an System.

We have previously isolated and characterized food-dwelling strains of () that are consumed naturally as part of the microbiota of table olives and raw milk cheeses. Despite being consumed at relatively high levels, the impact of such strains on the human gut microbiota is currently unclear. In the current study we evaluated the potential impact of food-dominant strains on the human gut microbiota using a continuous fecal fermentation system.

Photochemistry and anticancer activity of Pt(IV)Re(I) conjugates.

The photophysical and photochemical properties of two Pt(IV)Re(I) conjugates were studied both experimental and computational methods. Both conjugates exhibit modest photocytotoxicity against ovarian cancer cells. X-ray fluorescence microscopy showed that Pt and Re colocalize in cells whether they had been irradiated or not.

The biochemical fate of Ag ions in Staphylococcus aureus, Escherichia coli, and biological media.

Silver is commonly included in a range of household and medical items to provide bactericidal action. Despite this, the chemical fate of the metal in both mammalian and bacterial systems remains poorly understood. Here, we applied a metallomics approach using X-ray absorption spectroscopy (XAS) and size-exclusion chromatography hyphenated with inductively coupled plasma mass spectrometry (SEC-ICP-MS) to advance our understanding of the biochemical fate of silver ions in bacterial culture and cells, and the chemistry associated with these interactions.

Triazolyl-Functionalized N-Heterocyclic Carbene Half-Sandwich Compounds: Coordination Mode, Reactivity and in vitro Anticancer Activity.

We report investigations on the anticancer activity of organometallic [M (η -p-cymene/η -pentamethylcyclopentadienyl)] (M=Ru, Os, Rh, and Ir) complexes of N-heterocyclic carbenes (NHCs) substituted with a triazolyl moiety. Depending on the precursors, the NHC ligands displayed either mono- or bidentate coordination via the NHC carbon atom or as N,C-donors. The metal complexes were investigated for their stability in aqueous solution, with the interpretation supported by density functional theory calculations, and reactivity to biomolecules.

A synthetic consortium of 100 gut commensals modulates the composition and function in a colon model of the microbiome of elderly subjects.

Administration of cultured gut isolates holds promise for modulating the altered composition and function of the microbiota in older subjects, and for promoting their health. From among 692 initial isolates, we selected 100 gut commensal strains (MCC100) based on emulating the gut microbiota of healthy subjects, and retaining strain diversity within selected species. MCC100 susceptibility to seven antibiotics was determined, and their genomes were screened for virulence factor, antimicrobial resistance and bacteriocin genes.

Silver in biology and medicine: opportunities for metallomics researchers.

The antibacterial properties of silver have been known for centuries and the threat of antibiotic-resistant bacteria has led to renewed focus on the noble metal. Silver is now commonly included in a range of household and medical items to imbue them with bactericidal properties. Despite this, the chemical fate of the metal in biological systems is poorly understood.

Application of X-ray absorption and X-ray fluorescence techniques to the study of metallodrug action.

X-ray absorption spectroscopy and X-ray fluorescence microscopy are two synchrotron-based techniques frequently deployed either individually or in tandem to investigate the fates of metallodrugs and their biotransformation products in physiologically relevant sample material. These X-ray methods confer advantages over other analytical techniques in that they are nondestructive and require minimal chemical or physical manipulation of the sample before analysis, conserving both chemical and spatial information of the element(s) under investigation. In this review, we present selected examples of the use of X-ray absorption spectroscopy and X-ray fluorescence microscopy in studies of metallodrug speciation and localisation in vivo, in cell spheroids and in intact tissues and organs, and offer recent highlights in the advances of these techniques as they pertain to research on metallodrug action.