Acinetobacter baumannii thrives within eukaryotic cells, influencing persistence, treatment approaches, and progression of disease. We probed epithelial cell invasion by A. baumannii and the influence of antibodies raised to outer membrane protein 34 (Omp34) on epithelial interactions. We expressed and purified recombinant Omp34 and induced anti-Omp34 antibodies in Bagg albino or BALB/c mice. Omp34 was evaluated for acute toxicity in mice through histological analysis of six organs. The host cell line, A549, was exposed to both A. baumannii 19606 and a clinical isolate. The study also investigated serum resistance, adherence, internalization, and proliferation of A. baumannii in A549 cells, with and without anti-Omp34 sera, utilizing cell culture techniques and light microscopy. A549 cell viability was evaluated by A. baumannii challenge and exposure to anti-Omp34 sera. Actin disruption experiments using cytochalasin D probed microfilament and microtubule roles in A. baumannii invasion. Omp34 prompted antibody production without toxicity in mice. The serum showed bactericidal effects on both strains. Additionally, both A. baumannii strains were found to form biofilms. Omp34 serum was observed to decrease biofilm formation, bacterial adherence, internalization, and proliferation in A549 cells. Furthermore, the use of anti-Omp34 serum enhanced the post-infection survival of the host cell. Pre-exposure of A549 cells to cytochalasin D reduced bacterial internalization, highlighting the role of actin polymerization in the invasion process. Microscopic analysis revealed various interactions, such as adherence, membrane alterations, vacuolization, apoptosis, and cellular damage. Anti-Omp34 serum-exposed A549 cells were protected and showed reduced damage. The findings reveal that A. baumannii can significantly multiply intracellularly within host cells. This suggests the bacterium's ability to establish an environment conducive to its replication by preventing fusion with degradative lysosomes and inhibiting acidification. This finding contributes to the understanding of A. baumannii's intracellular persistence and highlights the role of Omp34 in influencing apoptosis, autophagy, and bacterial adherence, which may impact the development of effective treatments against A. baumannii infections.
- MeSH
- Acinetobacter baumannii * physiology immunology pathogenicity MeSH
- Bacterial Adhesion * MeSH
- Biofilms growth & development MeSH
- A549 Cells MeSH
- Epithelial Cells microbiology MeSH
- Acinetobacter Infections * microbiology immunology MeSH
- Humans MeSH
- Mice, Inbred BALB C MeSH
- Mice MeSH
- Antibodies, Bacterial * immunology MeSH
- Cell Survival MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
G protein-coupled receptors (GPCRs) play a crucial role in cell function by transducing signals from the extracellular environment to the inside of the cell. They mediate the effects of various stimuli, including hormones, neurotransmitters, ions, photons, food tastants and odorants, and are renowned drug targets. Advancements in structural biology techniques, including X-ray crystallography and cryo-electron microscopy (cryo-EM), have driven the elucidation of an increasing number of GPCR structures. These structures reveal novel features that shed light on receptor activation, dimerization and oligomerization, dichotomy between orthosteric and allosteric modulation, and the intricate interactions underlying signal transduction, providing insights into diverse ligand-binding modes and signalling pathways. However, a substantial portion of the GPCR repertoire and their activation states remain structurally unexplored. Future efforts should prioritize capturing the full structural diversity of GPCRs across multiple dimensions. To do so, the integration of structural biology with biophysical and computational techniques will be essential. We describe in this review the progress of nuclear magnetic resonance (NMR) to examine GPCR plasticity and conformational dynamics, of atomic force microscopy (AFM) to explore the spatial-temporal dynamics and kinetic aspects of GPCRs, and the recent breakthroughs in artificial intelligence for protein structure prediction to characterize the structures of the entire GPCRome. In summary, the journey through GPCR structural biology provided in this review illustrates how far we have come in decoding these essential proteins architecture and function. Looking ahead, integrating cutting-edge biophysics and computational tools offers a path to navigating the GPCR structural landscape, ultimately advancing GPCR-based applications. LINKED ARTICLES: This article is part of a themed issue Complexity of GPCR Modulation and Signaling (ERNST). To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v182.14/issuetoc.
- MeSH
- Protein Conformation MeSH
- Humans MeSH
- Receptors, G-Protein-Coupled * chemistry metabolism MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
- Review MeSH
Glioblastomas are aggressive brain tumors for which effective therapy is still lacking, resulting in dismal survival rates. These tumors display significant phenotypic plasticity, harboring diverse cell populations ranging from tumor core cells to dispersed, highly invasive cells. Neuron navigator 3 (NAV3), a microtubule-associated protein affecting microtubule growth and dynamics, is downregulated in various cancers, including glioblastoma, and has thus been considered a tumor suppressor. In this study, we challenge this designation and unveil distinct expression patterns of NAV3 across different invasion phenotypes. Using glioblastoma cell lines and patient-derived glioma stem-like cell cultures, we disclose an upregulation of NAV3 in invading glioblastoma cells, contrasting with its lower expression in cells residing in tumor spheroid cores. Furthermore, we establish an association between low and high NAV3 expression and the amoeboid and mesenchymal invasive phenotype, respectively, and demonstrate that overexpression of NAV3 directly stimulates glioblastoma invasive behavior in both 2D and 3D environments. Consistently, we observed increased NAV3 expression in cells migrating along blood vessels in mouse xenografts. Overall, our results shed light on the role of NAV3 in glioblastoma invasion, providing insights into this lethal aspect of glioblastoma behavior.
- MeSH
- Phenotype * MeSH
- Glioblastoma * pathology genetics metabolism MeSH
- Neoplasm Invasiveness * genetics MeSH
- Humans MeSH
- Membrane Proteins MeSH
- Microtubules metabolism MeSH
- Mice MeSH
- Cell Line, Tumor MeSH
- Brain Neoplasms * pathology genetics metabolism MeSH
- Cell Movement genetics physiology MeSH
- Nerve Tissue Proteins metabolism genetics MeSH
- Animals MeSH
- Check Tag
- Humans MeSH
- Mice MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
Starting point: Preventive programs for older adults should focus on promoting aging in their place of residence. A safe household without barriers is one condition for maintaining a high quality of life and supporting self-sufficiency. The occupational therapist plays a key role in evaluating the home environment and supervising follow-up interventions. Aim: This review study aims to clarify the role of occupational therapist interventions in the home environment of older adults and describe the most common and significant risks and subsequent modifications to the environment to create a safe home and prevent falls based on best practices. Methods: This is a review of published literature between 2013 and 2024 using the PRISMA methodology. The electronic databases Web of Science, Scopus, EBSCO, and PubMed were searched. Results: Of the 198 sources, 10 studies met the analysis criteria. Risky areas in older adult homes and possible interventions to increase safety are clearly listed. The areas with the greatest security risk are the bedrooms, bathrooms with toilets, and stairs. Various obstacles, including carpets, objects placed at an inappropriate height, a low toilet, or insufficient lighting, were among the most common causes of falls. Conclusions: Studies point to the importance of promoting self-sufficiency and raising awareness regarding aging modifications to the homes of older adults.
- Keywords
- domácí prostředí,
- MeSH
- Equipment Safety MeSH
- Safety MeSH
- Ergonomics MeSH
- Humans MeSH
- Aged, 80 and over MeSH
- Aged MeSH
- Accidental Falls * prevention & control MeSH
- Research MeSH
- Check Tag
- Humans MeSH
- Aged, 80 and over MeSH
- Aged MeSH
In the presented study, the cells of the glacial alga Ancylonema alaskanum collected in the Austrian Alps were analyzed. Algae were imaged both in their natural environment and in laboratory conditions using transmitted light and fluorescence microscopy. Using appropriate fluorochromes, the cell wall and cell organelles were studied. Oval nuclei located in the middle of the cell next to the chloroplasts and active mitochondria as well as lipid thylakoids of chloroplasts were imaged. Scanning electron microscopy showed that the surface of the algal cell wall was not significantly differentiated, and atomic force microscope imaging recorded little roughness. The SEM EDS analysis revealed that carbon, nitrogen, oxygen, and magnesium were the main components of the cells. It is worth emphasizing that the analyzed living algal cells were obtained directly from the glacier surface and demonstrated normal respiratory processes i.e. undisturbed physiological functions. Additionally, the mineral material accompanying the cells in their natural environment - fragments of the rock were imaged by Differential Interference Contrast microscopy and analyzed by Fourier Transform Infrared Spectroscopy. The study provides new data on the morphology and physicochemical characteristics of A. alaskanum, contributing to a more comprehensive characterization of their place in this harsh ecosystem.
- MeSH
- Ice Cover * MeSH
- Microscopy, Electron, Scanning MeSH
- Spectroscopy, Fourier Transform Infrared MeSH
- Publication type
- Journal Article MeSH
- Geographicals
- Austria MeSH
Ultraviolet (UV) radiation is a significant environmental stressor that affects the growth, physiology, and biochemical integrity of various organisms. This study investigates the potential protective effects of a zinc-cysteine (Zn-Cys) complex against UV-C radiation, with a focus on its impact on selected microalgae (Coccomyxa peltigerae and Parachlorella kessleri) and maize (Zea mays L.). We demonstrate that exposure of the Zn-Cys complex to UV-C (254 nm) results in the formation of fluorescent photoproducts, which exhibit UV-protective properties. The study reveals that Zn-Cys significantly mitigates UV-induced stress. In both microalgae species, the Zn-Cys complex enhanced growth even under UV exposure, with the 20% concentration showing the most robust protective effects. Further hyperspectral imaging confirmed the protective mechanism of Zn-Cys by monitoring changes in light reflectance in Parachlorella kessleri, indicating reduced photosynthetic efficiency and structural alterations induced by UV exposure, while Zn-Cys significantly mitigated these effects. In addition, in maize plants (Zea mays L.), Zn-Cys treatment preserved chlorophyll content and reduced polyphenol accumulation, indicating reduced oxidative stress. These findings highlight the potential of the Zn-Cys complex as a sustainable and cost-effective strategy for UV protection in both terrestrial and extraterrestrial agriculture, advancing our understanding of plant adaptation to extreme environments.
- MeSH
- Chlorophyta radiation effects drug effects MeSH
- Cysteine * chemistry pharmacology MeSH
- Photosynthesis drug effects radiation effects MeSH
- Coordination Complexes * chemistry pharmacology MeSH
- Zea mays radiation effects drug effects metabolism MeSH
- Microalgae radiation effects drug effects MeSH
- Ultraviolet Rays * MeSH
- Zinc * chemistry pharmacology MeSH
- Publication type
- Journal Article MeSH
Recent advances in optical sensing technologies underpin the development of high-performance, surface-sensitive analytical tools capable of reliable and precise detection of molecular targets in complex biological media in non-laboratory settings. Optical fibre sensors guide light to and from a region of interest, enabling sensitive measurements of localized environments. This positions optical fibre sensors as a highly promising technology for a wide range of biochemical and healthcare applications. However, their performance in real-world biological media is often limited by the absence of robust post-modification strategies that provide both high biorecognition and antifouling capabilities. In this study, we present the proof-of-concept antifouling and biorecognition performance of a polymer brush nano-coating synthesized at the sensing region of optical fibre long-period grating (LPG) sensors. Using a newly developed antifouling terpolymer brush (ATB) composed of carboxybetaine methacrylamide, sulfobetaine methacrylamide, and N-(2-hydroxypropyl)methacrylamide, we achieve state-of-the-art antifouling properties. The successful on-fibre ATB synthesis is confirmed through scanning electron microscopy (SEM), fluorescence microscopy, and label-free bio-detection experiments based on antibody-functionalized ATB-coated LPG optical fibres. Despite the challenges in handling optical fibres during polymerization, the resulting nano-coating retains its remarkable antifouling properties upon exposure to blood plasma and enables biorecognition element functionalization. These capabilities are demonstrated through the detection of IgG in buffer and diluted blood plasma using anti-IgG-functionalized ATB-coated sensing regions of LPG fibres in both label-based (fluorescence) and label-free real-time detection experiments. The results show the potential of ATB-coated LPG fibres for use in analytical biosensing applications.
The hippocampus (HPC) is essential for navigation and memory, tracking environmental continuity and change, including navigation relative to moving targets. CA1 ensembles expressing immediate-early gene (IEG) Arc and Homer1a RNA are contextually specific. While IEG expression correlates with HPC-dependent task demands, the effects of behavioral demands on IEG-expressing ensembles remain unclear. In three experiments, we investigated the effects of context switch, sustained presence, and task demands on dorso-proximal CA1 IEG+ ensembles in rats. Experiment 1 showed that the size of IEG+ (Arc, Homer1a RNA) ensembles dropped to baseline during uninterrupted 30-min exploration, reflecting familiarization, unless a context switch was present. Context-specificity of the ensembles depended on both environment identity and timing of the context switch. Experiment 2 found no effect of HPC-dependent mobile robot avoidance or HPC-independent avoidance of a stationary robot on IEG+ ensembles beyond mere exploration. Experiment 3 replicated these findings for c-Fos protein. The data suggest that IEG+ ensembles are driven by a context switch and shrink over time during sustained presence in the same environment. We found no evidence of task demands or their change affecting the size, stability over time, or task-specificity of IEG+ ensembles. These results shed light on the temporal dynamics of CA1 IEG+ ensembles, and their control by contextual and behavioral factors.
- MeSH
- Behavior, Animal physiology MeSH
- Cytoskeletal Proteins genetics metabolism MeSH
- CA1 Region, Hippocampal * metabolism physiology MeSH
- Homer Scaffolding Proteins * metabolism genetics MeSH
- Rats MeSH
- Genes, Immediate-Early * physiology MeSH
- Rats, Long-Evans * MeSH
- Nerve Tissue Proteins genetics metabolism MeSH
- Animals MeSH
- Check Tag
- Rats MeSH
- Male MeSH
- Animals MeSH
- Publication type
- Journal Article MeSH
Carbonaceous aerosols (CA), composed of black carbon (BC) and organic matter (OM), significantly impact the climate. Light absorption properties of CA, particularly of BC and brown carbon (BrC), are crucial due to their contribution to global and regional warming. We present the absorption properties of BC (bAbs,BC) and BrC (bAbs,BrC) inferred using Aethalometer data from 44 European sites covering different environments (traffic (TR), urban (UB), suburban (SUB), regional background (RB) and mountain (M)). Absorption coefficients showed a clear relationship with station setting decreasing as follows: TR > UB > SUB > RB > M, with exceptions. The contribution of bAbs,BrC to total absorption (bAbs), i.e. %AbsBrC, was lower at traffic sites (11-20 %), exceeding 30 % at some SUB and RB sites. Low AAE values were observed at TR sites, due to the dominance of internal combustion emissions, and at some remote RB/M sites, likely due to the lack of proximity to BrC sources, insufficient secondary processes generating BrC or the effect of photobleaching during transport. Higher bAbs and AAE were observed in Central/Eastern Europe compared to Western/Northern Europe, due to higher coal and biomass burning emissions in the east. Seasonal analysis showed increased bAbs, bAbs,BC, bAbs,BrC in winter, with stronger %AbsBrC, leading to higher AAE. Diel cycles of bAbs,BC peaked during morning and evening rush hours, whereas bAbs,BrC, %AbsBrC, AAE, and AAEBrC peaked at night when emissions from household activities accumulated. Decade-long trends analyses demonstrated a decrease in bAbs, due to reduction of BC emissions, while bAbs,BrC and AAE increased, suggesting a shift in CA composition, with a relative increase in BrC over BC. This study provides a unique dataset to assess the BrC effects on climate and confirms that BrC can contribute significantly to UV-VIS radiation presenting highly variable absorption properties in Europe.
- MeSH
- Aerosols * analysis MeSH
- Air Pollutants analysis MeSH
- Environmental Monitoring MeSH
- Particulate Matter analysis MeSH
- Light MeSH
- Carbon * analysis MeSH
- Publication type
- Journal Article MeSH
- Geographicals
- Europe MeSH
Cyanobacterial harmful blooms (CyanoHABs) pose a global ecological problem, and their lipopolysaccharides (LPS) are among the bioactive compounds they release. Previous studies on CyanoHAB-LPS from single cyanobacterial species have shown varying bioactivities in different in vitro cell models. In this study, we isolated LPS from 19 CyanoHAB samples collected at 18 water bodies in the Czech Republic over two consecutive seasons. The proportions of cyanobacteria, Gram-negative bacteria (G-), and other bacteria in the biomass were determined by qPCR, while the cyanobacterial genera were identified using light microscopy. In vitro models of keratinocytes (HaCaT), the intestinal epithelium (co-culture of differentiated Caco-2 cells and peripheral blood mononuclear cells - PBMC), and PBMC alone were treated with isolated LPS at concentrations of 50, 100, and 1 μg/ml, respectively. The endotoxin activities of these concentrations were within the range measured in the aquatic environment. Approximately 85-90% of the samples displayed biological activity. However, the potency of individual LPS effects and response patterns varied across the different in vitro models. Furthermore, the observed activities did not exhibit a clear correlation with the taxonomic composition of the phytoplankton community, the relative share of microbial groups in the biomass, endotoxin activity of the LPS, or LPS migration and staining pattern in SDS-PAGE. These findings suggest that the effects of CyanoHAB-LPS depend on the specific composition and abundance of various LPS structures within the complex environmental sample and their interactions with cellular receptors.
- MeSH
- Biomass MeSH
- Caco-2 Cells MeSH
- Leukocytes, Mononuclear MeSH
- Humans MeSH
- Lipopolysaccharides * toxicity MeSH
- Cyanobacteria * MeSH
- Harmful Algal Bloom MeSH
- Check Tag
- Humans MeSH
- Publication type
- Journal Article MeSH
