Living in big cities might involuntarily expose people to high levels of noise causing auditory and/or extra‐auditory impairments, including adverse effects on central nervous system (CNS) areas such ...as the hippocampus. In particular, CNS development is a very complex process that can be altered by environmental stimuli. We have previously shown that noise exposure of developing rats can induce hippocampal‐related behavioral alterations. However, noise‐induced biochemical alterations had not been studied yet. Thus, the aim of this work was to assess whether early noise exposure can affect rat hippocampal oxidative state and aminoacidergic neurotransmission tone. Additionally, the effectiveness of an enriched environment (EE) as a neuroprotective strategy was evaluated. Male Wistar rats were exposed to different noise schemes at 7 or 15 days after birth. Upon weaning, some animals were transferred to an EE whereas others were kept in standard cages. Short‐ and long‐term measurements were performed to evaluate reactive oxygen species, thioredoxins levels and catalase activity as indicators of hippocampal oxidative status as well as glutamic acid decarboxylase and a subtype of glutamate transporter to evaluate aminoacidergic neurotransmission tone. Results showed noise‐induced changes in hippocampal oxidative state and aminoacidergic neurotransmission markers that lasted until adolescence and differed according to the scheme and the age of exposure. Finally, EE housing was effective in preventing some of these changes. These findings suggest that CNS development seems to be sensitive to the effects of stressors such as noise, as well as those of an environmental stimulation, favoring prompt and lasting molecular changes.
Aqueous suspensions of microfibrillated cellulose obtained by a high pressure homogenization process were freeze-dried after solvent exchange into tert-butanol. The resulting aerogels, which ...displayed a remarkable open morphology with a surface area reaching 100 m2/g, were subjected to a gas-phase esterification with palmitoyl chloride. Under these conditions, variations of the reaction temperature from 100 to 200 °C, of the reaction time from 0.5 to 2 h, and of the initial quantity of reagent, led to the preparation of a library of cellulose palmitates with DS varying from zero to 2.36. These products were characterized by gravimetry, FTIR, and 13C solid-state NMR spectroscopy. Of special interest were the cellulose palmitate samples of low DS in the range of 0.1–0.4, which corresponded to hydrophobic cellulose microfibrils exclusively esterified at their surface while keeping intact their inner structure.
Arbuscular mycorrhizal (AM) symbiosis alleviates drought stress in plants. However, the intimate mechanisms involved, as well as its effect on the production of signalling molecules associated with ...the host plant–AM fungus interaction remains largely unknown. In the present work, the effects of drought on lettuce and tomato plant performance and hormone levels were investigated in non‐AM and AM plants. Three different water regimes were applied, and their effects were analysed over time. AM plants showed an improved growth rate and efficiency of photosystem II than non‐AM plants under drought from very early stages of plant colonization. The levels of the phytohormone abscisic acid, as well as the expression of the corresponding marker genes, were influenced by drought stress in non‐AM and AM plants. The levels of strigolactones and the expression of corresponding marker genes were affected by both AM symbiosis and drought. The results suggest that AM symbiosis alleviates drought stress by altering the hormonal profiles and affecting plant physiology in the host plant. In addition, a correlation between AM root colonization, strigolactone levels and drought severity is shown, suggesting that under these unfavourable conditions, plants might increase strigolactone production in order to promote symbiosis establishment to cope with the stress.
The current work shows a comprehensive study covering the effects of drought on plant physiology and mycorrhizal (AM) colonization. We propose that AM symbiosis alleviates drought stress by altering the hormonal profiles and affecting plant physiology in the host plant. A correlation between AM colonization, strigolactone levels and drought severity is shown for the first time.
Alcohol intake and exposure to noise are common activities of human adolescents performed in entertainment contexts worldwide that can induce behavioural disturbances. Therefore, the aim of the ...present work was to investigate in an experimental model of adolescent animals whether noise exposure and intermittent ethanol intake, when present individually or sequentially, might be able to modify different behaviours. Adolescent Wistar rats of both sexes were subjected to voluntary intermittent ethanol intake for 1 week followed by exposure to noise for 2 h and tested in a battery of behavioural tasks. Data show that males exposed to noise experienced a deficit in associative memory (AM), increase in anxiety‐like behaviours (ALB) and altered reaction to novelty (RN) when compared with sham animals, whereas females also showed an increase in risk assessment behaviours (RABs) and a decrease in exploratory activity (EA). In contrast, ethanol intake induced an increase in RAB and RN in males and females, whereas females also showed a deficit in AM and EA as well as an increase in ALB. When ethanol was ingested before noise exposure, most parameters were counteracted both in male and females, but differed among sexes. In consequence, it could be hypothesized that an environmental acute stressor like noise might trigger a behavioural counteracting induced by a previous repeated exposure to a chemical agent such as ethanol, leading to a compensation of a non‐adaptive behaviour and reaching a better adjustment to the environment.
Adolescent Wistar rats were subjected to either voluntary intermittent ethanol intake for 1 week, exposure to noise for 2 h or both and tested in a battery of behavioural tasks. It could be hypothesized that the presence of an environmental acute stressor such as noise might be enough to induce a behavioural counteracting of the changes observed after a repeated exposure to a chemical agent, leading to a compensation of a non‐adaptive behaviour to reach a better adjustment to the environment.
As early as 1991 Ochiai et al. reported that an acid‐activated form of phenyliodine diacetate, PhI(OAc)2, undergoes a reaction with propargyl‐silanes, germanes and stannanes to give the ...ortho‐propargyl iodobenzene. This formal C−H alkylation was proposed to take place through an unusual (even to date) iodonio‐based 3,3 rearrangement of an intermediate allenylsilane. Although this mechanistic principle has been invoked in related iodane‐directed C−H coupling reaction, some underlying principles have remained unaddressed, and the reaction rarely employed. Herein, DFT evidence for a mechanism best described as iodine‐guided electrophilic aromatic substitution is presented. Using a newly optimized reaction protocol that significantly reduces the undesired reduction process, the potency of the method is showcased through the synthesis of >40 structurally diverse ortho‐iodo propargyl (or allenyl) arenes.
Going hypervalent: Although the formation of ortho‐propargyliodobenzene through a reaction of the hypervalent iodine species PhI(OAc)2 with propargylsilanes has been known since early 1990s, this reaction has been largely overlooked synthetically. Presented herein is a revised protocol for this transformation, demonstrating an efficient formation of >40 diverse ortho‐propargyliodoarene cores. DFT evidence is also given for a low‐energy asynchronous cyclic transition state differing from that for a classical Claisen rearrangement process.
With the goal of an efficient and selective surface hydrophobization for subsequent colloidal dispersion into non-polar media, cellulose nanocrystals (CNCs) were transformed into aerogels of high ...surface area, prepared by freeze-drying dilute CNC suspensions in mixtures of water and t-BuOH of various compositions. In the best case, namely with dispersions in a medium consisting of 20 parts of water and 80 parts of t-BuOH (w/w), freeze-dried aerogels having specific areas as high as 160 m super(2) g super(-1) and a widely open texture were obtained. These aerogels were then subjected to a gas-phase esterification process resulting from the action of palmitoyl chloride vapors. By varying the process parameters, palmitoylated CNCs presenting degrees of substitution (DS) ranging from 0.1 to nearly 2 - deduced from solid state super(13)C NMR analysis - could be obtained. Of particular interest, the palmitoylated CNCs having a DS in the range of 0.3/0.8 still kept their native crystalline core, but their surface was hydrophobized. These characteristics allowed them to be readily dispersible into hydrophobic non-polar liquids, such as toluene, to yield non-flocculating suspensions showing transient birefringence under stirring. For higher DS values, the palmitoylation progress had the effect of diminishing the lateral size of the CNC crystalline cores, while adding at their remaining surface shells of highly modified cellulose chains easily soluble or swollen in apolar solvents. The resulting products thus yielded viscous isotropic media no longer birefringent under stirring when dispersed into toluene. Comparative classical derivatization experiments with palmitoyl chloride, performed with CNCs suspended in DMF, gave similar results. Thus, the CNCs in the optimized aerogels showed accessibility and reactivity comparable to those of CNCs dispersed in appropriate liquids. The gas-phase derivatization of nanocellulose aerogels appears therefore as an attractive and efficient process for preparing surface treated nanocelluloses.
Metal complexes have gained a huge interest in the biomedical research in the last decade because of the access to unexplored chemical space with regards to organic molecules and to present ...additional functionalities to act simultaneously as diagnostic and therapeutic agents. Herein, we evaluated the interaction of two polytopic polyaza ligands and their zinc complexes with DNA and RNA by UV thermal denaturation, fluorescence and circular dichroism spectroscopic assays. The zinc coordination was investigated by X-ray diffraction and afforded the structure of the binuclear zinc complex of
PYPOD
. Thermal denaturation of DNA and RNA and fluorimetry analysis revealed preferential binding of the zinc-
PHENPOD
complexes towards GC-containing DNA in contrast to the free ligands. On the other hand,
PYPOD
metal complexes, compared to the free ligand, stabilized AT-based DNA (B-form) better than AU-RNA (A-form). With regards to single stranded RNA, the binuclear complex of
PHENPOD
and the free ligand can efficiently identify polyadenylic acid (poly A) among other RNA sequences by circular dichroism spectroscopy. The antimicrobial activity in
S. aureus
and
E. coli
bacteria showed the highest activity for the free ligands and their trinuclear zinc complexes. This work can provide valuable insights into the impact of the nuclearity of polytopic polyaza ligands in the binding to DNA/RNA and the antimicrobial effect.
Two polytopic ligands and their zinc complexes show a high interaction with DNA/RNA and different recognition abilities of the nucleic acids depending on the base composition. The antimicrobial activity is higher for the free ligands.
The immune system plays a critical role in cancer, including lung cancer, which is the leading cause of cancer-related deaths worldwide. Immunotherapy, particularly immune checkpoint blockade, has ...revolutionized the treatment of lung cancer, but a large subset of patients either do not respond or develop resistance. Exosomes, essential mediators of cell-to-cell communication, exert a profound influence on the tumor microenvironment and the interplay between cancer and the immune system. This review focuses on the role of tumor-derived exosomes and immune cells-derived exosomes in the crosstalk between these cell types, influencing the initiation and progression of lung cancer. Depending on their cell of origin and microenvironment, exosomes can contain immunosuppressive or immunostimulatory molecules that can either promote or inhibit tumor growth, thus playing a dual role in the disease. Furthermore, the use of exosomes in lung cancer immunotherapy is discussed. Their potential applications as cell-free vaccines and drug delivery systems make them an attractive option for lung cancer treatment. Additionally, exosomal proteins and RNAs emerge as promising biomarkers that could be employed for the prediction, diagnosis, prognosis and monitoring of the disease. In summary, this review assesses the relationship between exosomes, lung cancer, and the immune system, shedding light on their potential clinical applications and future perspectives.
Heat shock protein 90 (HSP90) plays an essential role in lung adenocarcinoma, acting as a key chaperone involved in the correct functioning of numerous highly relevant protein drivers of this ...disease. To this end, HSP90 inhibitors have emerged as promising therapeutic strategies, even though responses to them have been limited to date. Given the need to maximize treatment efficacy, the objective of this study was to use isobaric tags for relative and absolute quantitation (iTRAQ)-based proteomic techniques to identify proteins in human lung adenocarcinoma cell lines whose basal abundances were correlated with response to HSP90 inhibitors (geldanamycin and radicicol derivatives). From the protein profiles identified according to response, the relationship between lactate dehydrogenase B (LDHB) and DNA topoisomerase 1 (TOP1) with respect to sensitivity and resistance, respectively, to geldanamycin derivatives is noteworthy. Likewise, rhotekin (RTKN) and decaprenyl diphosphate synthase subunit 2 (PDSS2) were correlated with sensitivity and resistance to radicicol derivatives. We also identified a relationship between resistance to HSP90 inhibition and the p53 pathway by glucose deprivation. In contrast, arginine biosynthesis was correlated with sensitivity to HSP90 inhibitors. Further study of these outcomes could enable the development of strategies to improve the clinical efficacy of HSP90 inhibition in patients with lung adenocarcinoma.
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