Iridium(iii) complexes of 1,2,4-triazines as potential bioorthogonal reagents: metal coordination facilitates luminogenic reaction with strained cyclooctynes

In this paper we describe unprecedented Ir(III) complexes of 5-(2-pyridyl)-1,2,4-triazine and their reactivity towards the strained cyclooctyne BCN. The coordination of a 1,2,4-triazine ring to an iridium(III) ion drastically increases the speed of the reaction, showing the second order rate constant of 8 M−1 s−1, the record value to date for a triazine-BCN reaction

Adatom controlled emergence of high hardness in biocompatible beta-Ti3Au intermetallic thin film surfaces

There is growing international interest in hard biocompatible thin film surface coatings to extend the lifetime of medical implants. Parameters of the physical vapour deposition technique can be utilized to fine tune the microstructure and resulting properties of the growing thin film surface by modifying the adatom mobility of the incoming species. This work investigates the evolution of high hardness and biocompatibility of sputter deposited beta-Ti3Au intermetallic thin film surfaces as a function of growth temperature and pressure. Titanium and gold are sputtered in an optimised 3:1 ratio over glass and Ti6Al4V substrates at varying pressures of 0.3 to 1.2 Pa and temperatures of 25 to 450°C. The microstructure and crystallinity of the deposited films improved with reduction in pressure from 1.2 to 0.3 Pa but development of the β-Ti3Au intermetallic compound occurred at temperatures above 350˚C. The density of the films also increased with reducing pressure, whereas improvement in their columnar structure was observed with increasing substrate temperature. These microstructural changes caused by adatom mobility variation, led to the emergence of superior mechanical surface hardness, reaching a peak value of 12.5 GPa for films grown at 0.3 Pa and 450°C. All thin film surfaces were highly biocompatible with ion leaching levels below 1 ppm, and films deposited at lower pressure exhibited much safer cytotoxic profiles against L929 mouse fibroblasts. This work demonstrates the emergence of high hardness and biocompatibility in Ti3Au thin film surfaces with potential as next generation medical implant coating materials

Mechanical performance of biocompatible Ti-Au thin films grown on glass and Ti6Al4V substrates

Ti-Au intermetallic based material systems are being extensively studied to develop hard and wear resistant biocompatible thin film coatings over implant devices to extend their lifetime 1, 2. However, the measurement of these mechanical characteristics depends upon factors such as surface properties of the substrates and their temperature during thin film deposition. In this work, Ti-Au thin films were deposited by magnetron sputtering on both glass and Ti6Al4V substrates at two different temperatures. These films were studied for their mechanical properties by the nanoindentation technique in both load control and displacement control modes using a Berkovich tip. XRD patterns and cross section SEM images detail the microstructure while AFM images present the surface morphology of these Ti-Au thin films. Biocompatibility of the films is verified by cytotoxicity tests on L929 mouse fibroblast cells using Alamar blue reagent and the ions leaching in the film extracts is measured using the ICPOEMS technique. Standard deviation for hardness of films on glass substrates is ~4 times lower than that on Ti6Al4V substrates and is corelated to a corresponding increase in surface roughness from 2nm for glass to 40nm for Ti6Al4V substrates 3. Increasing substrate temperature leads to an increase in film hardness from 5.1 to 8.9GPa and is related to the development of a super hard β phase of the Ti3Au intermetallic. The standard deviation of this peak mechanical hardness value of 8.9GPa is reduced by 3 times when measured in displacement control mode compared to the value measured in load control mode due of the effect of nanoindentation tip penetration depth. All the Ti-Au thin films exhibit excellent cytotoxicity values above 95% and ion leaching below 100ppb. This work presents a comparative study to optimize hardness measurement of Ti-Au thin films, critical for a better understanding of these super hard biocompatible coatings

Metabolic Disorder Dysfunction in Parkinson’s Disease: Bioenergetics, Redox Homeostasis and Central Carbon Metabolism

The loss of dopaminergic neurons in the substantia nigra pars compacta (SNpc) and the accumulation of protein inclusions (Lewy bodies) are the pathological hallmarks of Parkinson’s disease (PD). PD is triggered by genetic alterations, environmental/occupational exposures and aging. However, the exact molecular mechanisms linking these PD risk factors to neuronal dysfunction are still unclear. Alterations in redox homeostasis and bioenergetics (energy failure) are thought to be central components of neurodegeneration that contribute to the impairment of important homeostatic processes in dopaminergic cells such as protein quality control mechanisms, neurotransmitter release/metabolism, axonal transport of vesicles and cell survival. Importantly, both bioenergetics and redox homeostasis are coupled to neuro-glial central carbon metabolism. We and others have recently established a link between the alterations in central carbon metabolism induced by PD risk factors, redox homeostasis and bioenergetics and their contribution to the survival/death of dopaminergic cells. In this review, we focus on the link between metabolic dysfunction, energy failure and redox imbalance in PD, making an emphasis in the contribution of central carbon (glucose) metabolism. The evidence summarized here strongly supports the consideration of PD as a disorder of cell metabolism

Polyphenolics, glucosinolates and isothiocyanates profiling of aerial parts of \u3ci\u3eNasturtium officinale\u3c/i\u3e (Watercress)

Watercress (Nasturtium officinale) is a rich source of secondary metabolites with disease-preventing and/or health-promoting properties. Herein, we have utilized extraction procedures to isolate fractions of polyphenols, glucosinolates and isothiocyanates to determine their identification, and quantification. In doing so, we have utilized reproducible analytical methodologies based on liquid chromatography with tandem mass spectrometry by either positive or negative ion mode. Due to the instability and volatility of isothiocyanates, we followed an ammonia derivatization protocol which converts them into respective ionizable thiourea derivatives. The analytes’ content distribution map was created on watercress flowers, leaves and stems. We have demonstrated that watercress contains significantly higher levels of gluconasturtiin, phenethyl isothiocyanate, quercetin-3-O-rutinoside and isorhamnetin, among others, with their content decreasing from flowers (82.11 ± 0.63, 273.89 ± 0.88, 1459.30 ± 12.95 and 289.40 ± 1.37 ng/g of dry extract respectively) to leaves (32.25 ± 0.74, 125.02 ± 0.52, 1197.86 ± 4.24 and 196.47 ± 3.65 ng/g of det extract respectively) to stems (9.20 ± 0.11, 64.7 ± 0.9, 41.02 ± 0.18, 65.67 ± 0.84 ng/g of dry extract respectivbely). Pearson’s correlation analysis has shown that the content of isothiocyanates doesn’t depend only on the bioconversion of individual glucosinolates but also on other glucosinolates of the same group. Overall, we have provided comprehensive analytical data of the major watercress metabolites thereby providing an opportunity to exploit different parts of watercress for potential therapeutic applications

Oxidative Stress, Redox Signaling, and Autophagy: Cell Death \u3ci\u3eVersus\u3c/i\u3e Survival

Significance: The molecular machinery regulating autophagy has started becoming elucidated, and a number of studies have undertaken the task to determine the role of autophagy in cell fate determination within the context of human disease progression. Oxidative stress and redox signaling are also largely involved in the etiology of human diseases, where both survival and cell death signaling cascades have been reported to be modulated by reactive oxygen species (ROS) and reactive nitrogen species (RNS). Recent Advances: To date, there is a good understanding of the signaling events regulating autophagy, as well as the signaling processes by which alterations in redox homeostasis are transduced to the activation/regulation of signaling cascades. However, very little is known about the molecular events linking them to the regulation of autophagy. This lack of information has hampered the understanding of the role of oxidative stress and autophagy in human disease progression. Critical Issues: In this review, we will focus on (i) the molecular mechanism by which ROS/RNS generation, redox signaling, and/or oxidative stress/damage alter autophagic flux rates; (ii) the role of autophagy as a cell death process or survival mechanism in response to oxidative stress; and (iii) alternative mechanisms by which autophagy-related signaling regulate mitochondrial function and antioxidant response. Future Directions: Our research efforts should now focus on understanding the molecular basis of events by which autophagy is fine tuned by oxidation/reduction events. This knowledge will enable us to understand the mechanisms by which oxidative stress and autophagy regulate human diseases such as cancer and neurodegenerative disorders

Evaluation of Bioactive Properties of Lipophilic Fractions of Edible and Non-Edible Parts of \u3ci\u3eNasturtium officinale\u3c/i\u3e (Watercress) in a Model of Human Malignant Melanoma Cells

Watercress is an enriched source of phenethyl isothiocyanate (PEITC), among other phytochemicals, with an antioxidant capacity. The aim of this study was to (i) chemically characterize and (ii) biologically evaluate the profile of the main health-promoting compounds contained in edible (i.e., mixture of leaves and lateral buds) and non-edible (i.e., stems) parts of watercress in an in vitro model of malignant melanoma consisting of human malignant melanoma (A375), non-melanoma (A431) and keratinocyte (HaCaT) cells. The extraction of the main constituents of watercress was performed by subjecting the freeze-dried edible and non-edible samples through different extraction protocols, whereas their concentration was obtained utilizing analytical methodologies. In addition, cell viability was evaluated by the Alamar Blue assay, whereas levels of oxidative stress and apoptosis were determined by commercially available kits. The edible watercress sample contained a higher amount of various nutrients and phytochemicals in the hexane fraction compared to the non-edible one, as evidenced by the presence of PEITC, phenolics, flavonoids, pigments, ascorbic acid, etc. The cytotoxicity potential of the edible watercress sample in the hexane fraction was considerably higher than the non-edible one in A375 cells, whereas A431 and HaCaT cells appeared to be either more resistant or minimally affected, respectively. Finally, levels of oxidative stress and apoptotic induction were increased in both watercress samples, but the magnitude of the induction was much higher in the edible than the non-edible watercress samples. Herein, we provide further evidence documenting the potential development of watercress extracts (including watercress waste by-products) as promising anti-cancer agent(s) against malignant melanoma cells

Toxicity Profiling of Biosurfactants Produced by Novel Marine Bacterial Strains

Surface active agents (SAAs), currently used in modern industry, are synthetic chemicals produced from non-renewable sources, with potential toxic impacts on humans and the environment. Thus, there is an increased interest for the identification and utilization of natural derived SAAs. As such, the marine environment is considered a promising source of biosurfactants with low toxicity, environmental compatibility, and biodegradation compared to their synthetic counterparts. MARISURF is a Horizon 2020 EU-funded project aiming to identify and functionally characterize SAAs, derived from a unique marine bacterial collection, towards commercial exploitation. Specifically, rhamnolipids produced by Marinobacter MCTG107b and Pseudomonas MCTG214(3b1) strains were previously identified and characterized while currently their toxicity profile was assessed by utilizing well-established methodologies. Our results showed a lack of cytotoxicity in in vitro models of human skin and liver as indicated by alamar blue and propidium iodide assays. Additionally, the use of the single gel electrophoresis assay, under oxidative stress conditions, revealed absence of any significant mutagenic/anti-mutagenic potential. Finally, both 2,2’-azino-bis (3-ethylbenzothiazoline-6-sulphonicacid) (ABTS) and 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) cell-free assays, revealed no significant anti-oxidant capacity for neither of the tested compounds. Consequently, the absence of significant cytotoxicity and/or mutagenicity justifies their commercial exploitation and potential development into industrial end-user applications as natural and environmentally friendly biosurfactants

Multi-gene panel testing and association analysis in Cypriot breast cancer cases and controls

Introduction: It is estimated that around 5% of breast cancer cases carry pathogenic variants in established breast cancer susceptibility genes. However, the underlying prevalence and gene-specific population risk estimates in Cyprus are currently unknown.Methods: We performed sequencing on a population-based case-control study of 990 breast cancer cases and 1094 controls from Cyprus using the BRIDGES sequencing panel. Analyses were conducted separately for protein-truncating and rare missense variants.Results: Protein-truncating variants in established breast cancer susceptibility genes were detected in 3.54% of cases and 0.37% of controls. Protein-truncating variants in BRCA2 and ATM were associated with a high risk of breast cancer, whereas PTVs in BRCA1 and PALB2 were associated with a high risk of estrogen receptor (ER)-negative disease. Among participants with a family history of breast cancer, PTVs in ATM, BRCA2, BRCA1, PALB2 and RAD50 were associated with an increased risk of breast cancer. Furthermore, an additional 19.70% of cases and 17.18% of controls had at least one rare missense variant in established breast cancer susceptibility genes. For BRCA1 and PALB2, rare missense variants were associated with an increased risk of overall and triple-negative breast cancer, respectively. Rare missense variants in BRCA1, ATM, CHEK2 and PALB2 domains, were associated with increased risk of disease subtypes.Conclusion: This study provides population-based prevalence and gene-specific risk estimates for protein-truncating and rare missense variants. These results may have important clinical implications for women who undergo genetic testing and be pivotal for a substantial proportion of breast cancer patients in Cyprus