Impaired Integrated Stress Response and Mitochondrial Integrity Modulate Genotoxic Stress Impact and Lower the Threshold for Immune Signalling.

Mitochondria-nucleus communication during stress dictates cellular fate with consequences on the etiopathology of multiple age-related diseases. Impaired mitochondrial quality control through loss of function of the mitochondrial protease HtrA2 associates with accumulation of damaged mitochondria and triggers the integrated stress response, implicating the transcription factor CHOP. Here we have employed a combined model of impaired mitochondria quality control, namely HtrA2 loss of function, and/or integrated stress response, namely CHOP loss of function, and genotoxicity to address the distinctive roles of these cellular components in modulating intracellular and intercellular responses. The genotoxic agents employed were cancer therapeutic agents such as irradiation with X-ray and protons or treatment with the radiomimetic bleomycin. The irradiation had an enhanced effect in inducing DNA damage in cells with CHOP loss of function, while the bleomycin treatment induced more DNA damage in all the transgenic cells as compared to the control. The genetic modifications impaired the transmission of DNA damage signalling intercellularly. Furthermore, we have dissected the signalling pathways modulated by irradiation in selected genotypes with RNA sequencing analysis. We identified that loss of HtrA2 and CHOP function, respectively, lowers the threshold where irradiation may induce the activation of innate immune responses via cGAS-STING; this may have a significant impact on decisions for combined therapeutic approaches for various diseases.

Electrochemical evaluation of proton beam radiation effect on the B16 cell culture.

The interaction of radiation with matter takes place through energy transfer and is accomplished especially by ionized atoms or molecules. The effect of radiation on biological systems involves multiple physical, chemical and biological steps. Direct effects result in a large number of reactive oxygen species (ROS) within and outside and inside of the cells as well, which are responsible for oxidative stress. Indirect effects are defined as alteration of normal biological processes and cellular components (DNA, protein, lipids, etc.) caused by the reactive oxygen species directly induced by radiation. In this work, a classical design of an electrochemical (EC) three-electrodes system was employed for analyzing the effects of proton beam radiation on melanoma B16 cell line. In order to investigate the effect of proton radiation on the B16 cells, the cells were grown on the EC surface and irradiated. After optimization of the experimental set-up and dosimetry, the radiobiological experiments were performed at doses ranging between 0 and 2 Gy and the effect of proton beam irradiation on the cells was evaluated by the means of cyclic voltammetry and measuring the open circuit potential between working and reference electrodes.

The impact of COVID-19 pandemic on food waste behaviour of young people.

The aim of this research is to analyse the way young people perceive the food waste process, as well as the determinants and the impact of the COVID-19 pandemic on the responsible behaviour of young people towards food waste. The research design involves a study on a sample of 375 students from Romanian universities and the development and validation of a model using SEM-PLS. Our findings show that the impact of the COVID-19 pandemic has led to more people exhibiting food waste reduction behaviour, an increased awareness for the ethics of food waste among young people, and increased awareness of the environmental consequences of food waste. The limits of the paper refer to non-probability sampling technique and sampling structure that is limited to a single country. The practical implications of the study highlight that this pandemic is a good moment to raise awareness among young people about food waste and we discuss possible strategies on this matter. Our research offers a new perspective on food waste in the conditions of current health crisis, and possible anticipated economic recession, in the future.

Lethal disseminated tuberculosis in patients under biological treatment - two clinical cases and a short review.

Tumour necrosis factor (TNF)-α inhibitors are highly used in Romania for the treatment of autoimmune disorders, such as rheumatoid arthritis (RA), psoriasis, inflammatory bowel diseases, and ankylosing spondylitis. Biological therapy using TNF-α inhibitors is very effective but is associated with an increased risk of opportunistic infections, including active tuberculosis. Here, two cases are presented of patients with RA and psoriasis under biological therapy who developed very aggressive forms of disseminated tuberculosis, with a rapid progression to death. The authors conclude that patients undergoing biological therapy require thorough evaluation prior to initiating treatment, followed by continuous and rigorous monitoring by a multidisciplinary team during biological treatment, particularly in countries with a high incidence of tuberculosis.

In Vitro Human Microbiota Response to Exposure to Silver Nanoparticles Biosynthesized with Mushroom Extract.

The ability to orally administer silver nanoparticles (AgNPs) in enteric capsules implies a direct interaction with the colon microbiota. The in vitro effect provides a portrayal of the functional properties under in vivo conditions. The purpose of this study was to describe a green AgNP synthesis process, using aqueous extract from Lactarius piperatus mushroom, and to characterize the nanomaterial. We determined its antimicrobial and antioxidant effects in vitro in the microbiota of healthy individuals via the GIS1 system-a colon transit simulator. Per the quantitative polymerase chain reaction (qPCR) results, the antimicrobial properties of the AgNPs affected the initial share of different enteric species by decreasing the Bacteroides, Enterobacteriaceae, and Lactobacillus populations and favoring the Bifidobacterium group. The association between AgNPs and wild mushroom L. piperatus extract had a synergistic antibacterial activity against various pathogenic microorganisms while the mushroom extract reduced biofilm formation. Administration of AgNP maintained its constant antioxidant status, and it was correlated with a reduction in ammonium compounds. The physicochemical characterization of these NPs complemented their biochemical characterization. The maximum ultraviolet-visible spectroscopy (UV-VIS) absorbance was observed at 440 nm, while the Fourier transform infrared (FT-IR) spectrum reached a peak at 3296 cm⁻1, which was correlated with the high-performance liquid chromatographic analysis (HPLC). The major phenolic compound was homogentisic acid. The size (49 ± 16 nm in diameter) and spherical shape of the NPs were correlated with their biological effects in vitro.

Atomic force microscopy study of morphological modifications induced by different decontamination treatments on Escherichia coli.

In this paper we used atomic force microscopy (AFM) to investigate the surface morphology of Escherichia coli, after being subjected to decontamination treatments, at sub-MICs levels (minimal inhibitory concentrations), with different disinfectants used in hospitals, pharmaceutical, food industry and even in our home, as an essential means to prevent the spreading of microorganisms. This article focuses on different morphological modifications adopted by E. coli cells as responses to the different modes of action of these substances. For high-resolution AFM images bacterial cells were immobilized on mica (Muscovite) disks. Each kind of treatment induces its distinct morphological changes, due to different mechanisms of action.

Modulating short tryptophan- and arginine-rich peptides activity by substitution with histidine.

BACKGROUND: High antimicrobial efficacy of short tryptophan-and arginine-rich peptides makes them good candidates in the fight against pathogens. Substitution of tryptophan and arginine by histidine could be used to modulate the peptides efficacy by optimizing their structures. METHODS: The peptide (RRWWRWWRR), reported to showed good antimicrobial efficacy, was used as template, seven new analogs being designed substituting tryptophan or arginine with histidine. The peptides' efficacy was tested against E. coli, B. subtilis and S. aureus. The cytotoxicity and hemolytic effect were evaluated and the therapeutic index was inferred for each peptide. Atomic force microscopy and molecular simulation were used to analyze the effects of peptides on bacterial membrane. RESULTS: The substitution of tryptophan by histidine proved to strongly modulate the antimicrobial activity, mainly by changing the peptide-to-membrane binding energy. The substitution of arginine has low effect on the antimicrobial efficacy. The presence of histidine residue reduced the cytotoxic and hemolytic activity of the peptides in some cases maintaining the same efficacy against bacteria. The peptides' antimicrobial activity was correlated to the 3D-hydrophobic moment and to a simple structure-based packing parameter. CONCLUSION: The results show that some of these peptides have the potential to become good candidates to fight against bacteria. The substitution by histidine proved to fine tune the therapeutic index allowing the optimization of the peptide structure mainly by changing its binding energy and 3D-hydrophobic moment. GENERAL SIGNIFICANCE: The short tryptophan reach peptides therapeutic index can be maximized using the histidine substitution to optimize their structure.

Long-term result of the Echols procedure for treating syringomyelia.

In 1974, a 9-year-old girl with syringomyelia and scoliosis was treated using the Echols procedure, a surgical technique that makes use of a metal stent to maintain drainage of fluid from the syrinx into the subarachnoid space. The patient presented to the authors' institution 34 years later with a history of progressive myelopathy and surgically treated deformities of the thoracic spine, lumbar spine, and right foot. Computer-assisted myelography indicated that the metal wire remained in place and that the syrinx had collapsed. Neurological examination and neurophysiological testing confirmed the presence of thoracic myelopathy, which may have been due to the wire tethering the thoracic spinal cord to the dorsal dura. This case is believed to be the only long-term report of the effects of the Echols procedure. The history of direct treatment of syringomyelia is reviewed and is contrasted with indirect treatment of syringomyelia, which relieves the condition by opening obstructed CSF pathways within the foramen magnum or spine.

D3 dopamine autoreceptors do not activate G-protein-gated inwardly rectifying potassium channel currents in substantia nigra dopamine neurons.

Substantia nigra (SN) dopamine neurons express D2 and D3 dopamine autoreceptors. A physiological role for the D3 receptor has not been identified, but an activation of G-protein-gated inwardly rectifying potassium (GIRK; also known as Kir3) channels is strongly implicated because D3 receptors activate channels composed of GIRK2 subunits in cell lines. We confirmed that acutely dissociated SN dopamine neurons indeed contain D3 and GIRK2 subunit mRNA using single-cell RT-PCR. We then tested whether D3 receptors activate GIRK currents in SN dopamine neurons by comparing acutely dissociated neurons from D2-/- receptor knock-out and congenic wild-type mice. In nearly all (14 of 15) wild-type SN dopamine neurons, the D2/D3 agonist quinpirole activated GIRK currents that were blocked by cesium. Quinpirole, however, elicited no GIRK currents in any SN dopamine neuron (0 of 13) derived from D2-/- receptor knock-out mice. The absence of quinpirole response was not caused by a lack of GIRK activity, because the GABAB receptor agonist baclofen continued to elicit these currents in the mutant neurons. Thus, it appears that D3 activation of GIRK currents in SN neurons does not occur or is exceedingly rare.

PIP(2) activates KCNQ channels, and its hydrolysis underlies receptor-mediated inhibition of M currents.

KCNQ channels belong to a family of potassium ion channels with crucial roles in physiology and disease. Heteromers of KCNQ2/3 subunits constitute the neuronal M channels. Inhibition of M currents, by pathways that stimulate phospholipase C activity, controls excitability throughout the nervous system. Here we show that a common feature of all KCNQ channels is their activation by the signaling membrane phospholipid phosphatidylinositol-bis-phosphate (PIP(2)). We show that wortmannin, at concentrations that prevent recovery from receptor-mediated inhibition of M currents, blocks PIP(2) replenishment to the cell surface. Moreover, we identify a C-terminal histidine residue, immediately proximal to the plasma membrane, mutation of which renders M channels less sensitive to PIP(2) and more sensitive to receptor-mediated inhibition. Finally, native or recombinant channels inhibited by muscarinic agonists can be activated by PIP(2). Our data strongly suggest that PIP(2) acts as a membrane-diffusible second messenger to regulate directly the activity of KCNQ currents.