Peripherally crowded cationic phthalocyanines as efficient photosensitizers for photodynamic therapy

Photodynamic therapy is a treatment modality of cancer based on the production of cytotoxic species upon the light activation of photosensitizers. Zinc phthalocyanine photosensitizers bearing four or eight bulky 2,6-di(pyridin-3-yl)phenoxy substituents were synthesized, and pyridyl moieties were methylated. The quaternized derivatives did not aggregate at all in water and retained their good photophysical properties. High photodynamic activity of these phthalocyanines was demonstrated on HeLa, MCF-7, and EA.hy926 cells with a very low EC50 of 50 nM (for the MCF-7 cell line) upon light activation while maintaining low toxicity in the dark (TC50 ≈ 600 μM), giving thus good phototherapeutic indexes (TC50/EC50) above 1400. The compounds localized primarily in the lysosomes, leading to their rupture after light activation. This induced an apoptotic cell death pathway with secondary necrosis because of extensive and swift damage to the cells. This work demonstrates the importance of a bulky and rigid arrangement of peripheral substituents in the development of photosensitizersThe work was supported by the Czech Science Foundation (19-14758Y), Charles University (PRIMUS/20/SCI/013, GAUK 1620219, SVV 260 550), and by the project EFSACDN (No. CZ.02.1.01/0.0/0.0/16_019/0000841) cofunded by the ERDF. For affiliations ‡, ∥, and ⊥, the work was supported by MINECO-Feder funds (CTQ2017-85393-P (T.T.), CTQ-2014-53673-P and CTQ-2017-89539-P (A.d.l.E.), PCIN-2017-042/EuroNanoMed2017-191, TEMPEAT (T.T.)). Affiliation ⊥ (IMDEA Nanociencia) also acknowledges support from the ‘Severo Ochoa’ Programme for Centres of Excellence in R&D (MINECO, Grant SEV2016-0686

The 2018 European heatwave led to stem dehydration but not to consistent growth reductions in forests

Heatwaves exert disproportionately strong and sometimes irreversible impacts on forest ecosystems. These impacts remain poorly understood at the tree and species level and across large spatial scales. Here, we investigate the effects of the record-breaking 2018 European heatwave on tree growth and tree water status using a collection of high-temporal resolution dendrometer data from 21 species across 53 sites. Relative to the two preceding years, annual stem growth was not consistently reduced by the 2018 heatwave but stems experienced twice the temporary shrinkage due to depletion of water reserves. Conifer species were less capable of rehydrating overnight than broadleaves across gradients of soil and atmospheric drought, suggesting less resilience toward transient stress. In particular, Norway spruce and Scots pine experienced extensive stem dehydration. Our high-resolution dendrometer network was suitable to disentangle the effects of a severe heatwave on tree growth and desiccation at large-spatial scales in situ, and provided insights on which species may be more vulnerable to climate extremes

Dynamics of Tryptophan Metabolic Pathways in Human Placenta and Placental-Derived Cells: Effect of Gestation Age and Trophoblast Differentiation.

L-Tryptophan is an essential amino acid and a precursor of several physiologically active metabolites. In the placenta, the serotonin and kynurenine metabolic pathways of tryptophan metabolism have been identified, giving rise to various molecules of neuroactive or immunoprotective properties, such as serotonin, melatonin, kynurenine, kynurenic acid, or quinolinic acid. Current literature suggests that optimal levels of these molecules in the fetoplacental unit are crucial for proper placenta functions, fetal development and programming. Placenta is a unique endocrine organ that, being equipped with a battery of biotransformation enzymes and transporters, precisely orchestrates homeostasis of tryptophan metabolic pathways. However, because pregnancy is a dynamic process and placental/fetal needs are continuously changing throughout gestation, placenta must adapt to these changes and ensure proper communication in the feto-placental unit. Therefore, in this study we investigated alterations of placental tryptophan metabolic pathways throughout gestation. Quantitative polymerase chain reaction (PCR) analysis of 21 selected genes was carried out in first trimester (n = 13) and term (n = 32) placentas. Heatmap analysis with hierarchical clustering revealed differential gene expression of serotonin and kynurenine pathways across gestation. Subsequently, digital droplet PCR, Western blot, and functional analyses of the rate-limiting enzymes suggest preferential serotonin synthesis early in pregnancy with a switch to kynurenine production toward term. Correspondingly, increased function and/or protein expression of serotonin degrading enzyme and transporters at term indicates efficient placental uptake and metabolic degradation of serotonin. Lastly, gene expression analysis in choriocarcinoma-derived cell lines (BeWo, BeWo b30, JEG-3) revealed dissimilar expression patterns and divergent effect of syncytialization compared to primary trophoblast cells isolated from human term placentas; these findings show that the commonly used in vitro placental models are not suitable to study placental handling of tryptophan. Altogether, our data provide the first comprehensive evidence of changes in placental homeostasis of tryptophan and its metabolites as a function of gestational age, which is critical for proper placental function and fetal development

Profiling of Tryptophan Metabolic Pathways in the Rat Fetoplacental Unit during Gestation

Placental homeostasis of tryptophan is essential for fetal development and programming. The two main metabolic pathways (serotonin and kynurenine) produce bioactive metabolites with immunosuppressive, neurotoxic, or neuroprotective properties and their concentrations in the fetoplacental unit must be tightly regulated throughout gestation. Here, we investigated the expression/function of key enzymes/transporters involved in tryptophan pathways during mid-to-late gestation in rat placenta and fetal organs. Quantitative PCR and heatmap analysis revealed the differential expression of several genes involved in serotonin and kynurenine pathways. To identify the flux of substrates through these pathways, Droplet Digital PCR, western blot, and functional analyses were carried out for the rate-limiting enzymes and transporters. Our findings show that placental tryptophan metabolism to serotonin is crucial in mid-gestation, with a subsequent switch to fetal serotonin synthesis. Concurrently, at term, the close interplay between transporters and metabolizing enzymes of both placenta and fetal organs orchestrates serotonin homeostasis and prevents hyper/hypo-serotonemia. On the other hand, the placental production of kynurenine increases during pregnancy, with a low contribution of fetal organs throughout gestation. Any external insult to this tightly regulated harmony of transporters and enzymes within the fetoplacental unit may affect optimal in utero conditions and have a negative impact on fetal programming

A Surveillance System for Enhancing the Safety of Rescue Teams

The article summarizes preliminary results of the research and development of a system focused on enhancing the safety of teams participating in the integrated rescue system managing extraordinary events or crisis situations (fire, mass disaster, release of harmful industrial substances), and on the support in the course of training. Individual partial technical solutions are mentioned, which should lead to providing automatized telemetric monitoring equipment in a more resistant form making it possible to recognize the nature and intensity of the motion, including the determination of the topical and total energy outputs, monitoring of environmental parameters (temperature, smoke, etc.) and back analysis of the intervention course or training in real time, and the monitoring of health-physiological parameters and signalling risk conditions (physical exhaustion, stress, overheating, etc.) under extreme measures

Stem quality assessment in European National Forest Inventories: an opportunity for harmonised reporting?

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Alkylamino derivatives of N-benzylpyrazine-2-carboxamide: synthesis and antimycobacterial evaluation

© The Royal Society of Chemistry. A series of alkylamino derivatives of N-benzylpyrazine-2-carboxamide was designed, synthesized and assayed in vitro for their antimycobacterial, antibacterial, antifungal as well as antiviral activities. Final structures were prepared from 6-chloro (1), 5-chloro (2) or 3-chloro (3) derivatives of N-benzylpyrazine-2-carboxamide by nucleophilic substitution of chlorine with n-alkylamines in the range from butylamine to octylamine (labelled a-e). Series 1a-e and 2a-e exerted higher activity against Mycobacterium tuberculosis H37Rv compared to the corresponding pattern compounds and the reference compound pyrazinamide. The most active derivatives reached an activity MIC = 4.6-10 μM (M. tbc H37Rv). More importantly, activity was also observed against other tested mycobacterial strains (including drug-resistant strains). Substitution of 3-chlorine was disadvantageous and led to completely inactive compounds 3a-e. Some compounds showed activity against Gram-positive bacterial strains (including MRSA) or influenza virus, but no antifungal activity was observed.status: publishe

Deriváty beta-Crinane Amaryllidaceae Alkaloid Haemanthamine jako vícecílové cílené ligandy pro Alzheimerovu chorobu

Twelve derivatives 1a-1m of the beta-crinane-type alkaloid haemanthamine were developed. All the semisynthetic derivatives were studied for their inhibitory potential against both acetylcholinesterase and butyrylcholinesterase. In addition, glycogen synthase kinase 3 beta (GSK-3 beta) inhibition potency was evaluated in the active derivatives. In order to reveal the availability of the drugs to the CNS, we elucidated the potential of selected derivatives to penetrate through the blood-brain barrier (BBB). Two compounds, namely 11-O-(2-methylbenzoyl)-haemanthamine (1j) and 11-O-(4-nitrobenzoyl)-haemanthamine (1m), revealed the most intriguing profile, both being acetylcholinesterase (hAChE) inhibitors on a micromolar scale, with GSK-3 beta inhibition properties, and predicted permeation through the BBB. In vitro data were further corroborated by detailed inspection of the compounds' plausible binding modes in the active sites of hAChE and hBuChE, which led us to provide the structural determinants responsible for the activity towards these enzymes.Bylo vyvinuto dvanáct derivátů la-lm alkaloidního hematoaminu beta-krinanu. Všechny semisyntetické deriváty byly studovány na inhibiční potenciál proti acetylcholinesteráze i butyrylcholinesteráze. Kromě toho byla v aktivních derivátech hodnocena inhibiční schopnost glykogen syntázy kinázy 3 beta (GSK-3 beta). Abychom odhalili dostupnost léčiv pro CNS, objasnili jsme potenciál vybraných derivátů proniknout hematoencefalickou bariérou (BBB). Dvě sloučeniny, jmenovitě 11-O- (2-methylbenzoyl) -haemanthamin (1j) a 11-O- (4-nitrobenzoyl) -haemanthamin (1m), odhalily nejzajímavější profil, obě jsou inhibitory acetylcholinesterázy (hAChE) na mikromolárním v měřítku, s inhibičními vlastnostmi GSK-3 beta a předpovězenou permeací BBB. Data in vitro byla dále potvrzena podrobnou inspekcí věrohodných vazebných režimů sloučenin v aktivních místech hAChE a hBuChE, což nás vedlo k poskytnutí strukturálních determinant odpovědných za aktivitu vůči těmto enzymům