Search Results (1,102)

Status epilepticus occurs when a seizure lasts more than five minutes or when multiple seizures occur with incomplete return to baseline. SE induces a myriad of pathological changes involving synaptic and extra-synaptic factors. The transition from a self-limiting seizure to a self-sustaining one is established by maladaptive receptor trafficking, whereby GABA_A receptors are progressively endocytosed while glutamatergic receptors (NMDA and AMPA) are transported to the synaptic membrane, causing excitotoxicity and alteration in glutamate-dependent downstream signaling. The subsequent influx of Ca²⁺ exposes neurons to increased levels of [Ca²⁺]i, which overwhelms mitochondrial buffering, resulting in irreversible mitochondrial membrane depolarization and mitochondrial injury. Oxidative stress resulting from mitochondrial leakage and increased production of reactive oxygen species activates the inflammasome and induces a damage-associated molecular pattern. Neuroinflammation perpetuates oxidative stress and exacerbates mitochondrial injury, thereby jeopardizing mitochondrial energy supply in a state of accelerated ATP consumption. Additionally, Ca²⁺ overload can directly damage neurons by activating enzymes involved in the breakdown of proteins, phospholipids, and nucleic acids. The cumulative effect of these effector pathways is neuronal injury and neuronal death. Surviving neurons undergo long-term alterations that serve as a substrate for epileptogenesis. This review highlights the multifaceted mechanisms underlying SE self-sustainability, pharmacoresistance, and subsequent epileptogenesis. Full article

This study aimed to investigate the efficacy of a composite coating composed of 150 mg/L ε-Poly-L-lysine (ε-PL) and 5 g/L chitosan (CTS) in extending the shelf life and maintaining the postharvest quality of fresh Tremella fuciformis. Freshly harvested T. fuciformis were treated by surface spraying, with distilled water serving as the control. The effects of the coating on storage quality, physicochemical properties, reactive oxygen species (ROS) metabolism, and membrane lipid metabolism were evaluated during storage at (25 ± 1) °C. The results showed that the ε-PL/CTS composite coating significantly retarded quality deterioration, as evidenced by reduced weight loss, maintained whiteness and color, and higher retention of soluble sugars, soluble solids, and soluble proteins. The coating also effectively limited water migration and loss. Mechanistically, the coated T. fuciformis exhibited enhanced antioxidant capacity, characterized by increased superoxide anion (O₂⁻) resistance capacity, higher activities of antioxidant enzymes (SOD, CAT, APX), and elevated levels of non-enzymatic antioxidants (AsA, GSH). This led to a significant reduction in malondialdehyde (MDA) accumulation, alongside improved DPPH radical scavenging activity and reducing power. Furthermore, the ε-PL/CTS coating preserved cell membrane integrity by inhibiting the activities of lipid-degrading enzymes (lipase, LOX, PLD), maintaining higher levels of key phospholipids (phosphatidylinositol and phosphatidylcholine), delaying phosphatidic acid accumulation, and consequently reducing cell membrane permeability. In conclusion, the ε-PL/CTS composite coating effectively extends the shelf life and maintains the quality of postharvest T. fuciformis by modulating ROS metabolism and preserving membrane lipid homeostasis. This study provides a theoretical basis and a practical approach for the quality control of fresh T. fuciformis. Full article

This study investigates how phospholipid headgroups influence passive membrane penetration and structural impact of four nitrogen-, sulfur-, and oxygen-containing heterocycles (NSO-HETs)—N-methyl-2-pyrrolidone (PIR), 1,4-dioxane (DIOX), oxane (OXA), and phenol (PHE). Using all-atom molecular dynamics simulations combined with Accelerated Weight Histogram free energy calculations, the passive transport of NSO-HETs across DPPC, DPPE, DPPA, and DPPG bilayers was characterized. DPPG showed the highest membrane affinity, increasing permeability (logP_memb/bulk) by 27–64% compared to DPPE, associated with the lowest permeability and tightest lipid packing. Free energy barriers are also decreased in DPPG relative to DPPE; PIR’s central barrier dropped from 19.2 kJ/mol (DPPE) to 16.6 kJ/mol (DPPG), while DIOX’s barrier decreased from 7.2 to 5.2 kJ/mol. OXA exhibited the lowest central barriers (1.2–2.2 kJ/mol) and uniquely accumulated at higher concentrations in the bilayer center than in bulk water, with free energy ranging from −3.4 to −5.9 kJ/mol. PHE and OXA caused significant bilayer thinning (up to 11%) and reduced lipid tail order, especially in DPPE and DPPA. Concentration effects were most pronounced in DPPE, where high solute loading disrupted lipid order and altered free energy profiles. These results highlight the crucial role of headgroup identity in modulating NSO-HET membrane permeability and structural changes. Full article

Vibrio parahaemolyticus is a major foodborne pathogen worldwide, responsible for seafood-associated poisoning. Among its toxin genes, tdh2 is the most critical. To investigate the role of tdh2 in V. parahaemolyticus under gastrointestinal conditions, we constructed tdh2 deletion and complementation strains and compared their survival under acid (pH 3 and 4) and bile stress (2%). The results showed that tdh2 expression was significantly upregulated under cold (4 °C) and bile stress (0.9%). Survival assays and PI staining revealed that the tdh2 mutant strain (VP: △tdh2) was more sensitive to acid and bile stress than the wild-type (WT), and this sensitivity was rescued by tdh2 complementation. These findings suggest that tdh2 plays a protective role in enhancing V. parahaemolyticus tolerance to acid and bile stress. In the VP: △tdh2 strain, seven genes were significantly upregulated and six were downregulated as a result of tdh2 deletion. These genes included VPA1332 (vtrA), VPA1348 (vtrB), VP2467 (ompU), VP0301 and VP1995 (ABC transporters), VP0527 (nhaR), and VP2553 (rpoS), among others. Additionally, LC-MS/MS analysis identified 12 differential metabolites between the WT and VP: △tdh2 strains, including phosphatidylserine (PS) (17:2 (9Z,12Z) /0:0 and 20:1 (11Z) /0:0), phosphatidylglycerol (PG) (17:0/0:0), flavin mononucleotide (FMN), and various nucleotides. The protective mechanism of tdh2 may involve preserving cell membrane permeability through regulation of ompU and ABC transporters and enhancing electron transfer efficiency via regulation of nhaR. The resulting reduction in ATP, DNA, and RNA synthesis—along with changes in membrane permeability and electron transfer due to decreased FMN—likely contributed to the reduced survival of the VP: △tdh2 strain. Meanwhile, the cells actively synthesized phospholipids to repair membrane damage, leading to increased levels of PS and PG. This study provides important insights into strategies for preventing and controlling food poisoning caused by tdh⁺ V. parahaemolyticus. Full article

T-2 toxin and HT-2 toxin are commonly found in agricultural products and animal feed, posing serious effects to both humans and animals. This study employed combination index (CI) modeling and metabolomics to assess the combined cytotoxic effects of T-2 and HT-2 on four porcine cell types: intestinal porcine epithelial cells (IPEC-J2), porcine Leydig cells (PLCs), porcine ear fibroblasts (PEFs), and porcine hepatocytes (PHs). Cell viability assays revealed a dose-dependent reduction in viability across all cell lines, with relative sensitivities in the order: IPEC-J2 > PLCs > PEFs > PHs. Synergistic cytotoxicity was observed at low concentrations, while antagonistic interactions emerged at higher doses. Untargeted metabolomic profiling identified consistent and significant metabolic perturbations in four different porcine cell lines under co-exposure conditions. Notably, combined treatment with T-2 and HT-2 resulted in a uniform downregulation of LysoPC (22:6), LysoPC (20:5), and LysoPC (20:4), implicating disruption of membrane phospholipid integrity. Additionally, glycerophospholipid metabolism was the most significantly affected pathway across all cell lines. Ether lipid metabolism was markedly altered in PLCs and PEFs, whereas PHs displayed a unique metabolic response characterized by dysregulation of tryptophan metabolism. This study identified markers of synergistic toxicity and common alterations in metabolic pathways across four homologous porcine cell types under the combined exposure to T-2 and HT-2 toxins. These findings enhance the current understanding of the molecular mechanisms underlying mycotoxin-induced the synergistic toxicity. Full article

Alzheimer’s dementia (AD) is a disease of the ageing brain. It begins in the hippocampal region with the epicentre in the entorhinal cortex, then gradually extends into adjacent brain areas involved in memory and cognition. The events which initiate the damage are unknown and under intense investigation. Localization to the hippocampus can now be explained by anatomical features of the blood vessels supplying this region. Blood supply and hence oxygen delivery to the area are jeopardized by poor flow through narrowed arteries. In genomic and metabolomic studies, the respiratory chain and mitochondrial pathways which generate ATP were leading pathways associated with AD. This review explores the notion that ATP depletion resulting from hippocampal hypoperfusion has a prime role in initiating damage. Sections cover sensing of ATP depletion and protective responses, vulnerable processes with very heavy ATP consumption (the malate shuttle, the glutamate/glutamine/GABA (γ-aminobutyric acid) cycle, and axonal transport), phospholipid disturbances and peroxidation by reactive oxygen species, hippocampal perfusion and the effects of hypertension, chronic hypoxia, and arterial vasospasm, and an overview of recent relevant genomic studies. The findings demonstrate strong scientific arguments for the proposal with increasing supportive evidence. These lines of enquiry should be pursued. Full article

This study developed phospholipid-based liposomes loaded with extract from wild thyme (Thymus serpyllum L.) tea processing residues to enhance polyphenol stability and delivery. Liposomes were prepared with phospholipids alone or combined with 10–30 mol% cholesterol or β-sitosterol. The effect of different lipid compositions on encapsulation efficiency (EE), particle size, polydispersity index (PDI), zeta potential, stability, thermal properties, diffusion coefficient, and diffusion resistance of the liposomes was investigated. Liposomes with 10 mol% sterols (either cholesterol or β-sitosterol) exhibited the highest EE of polyphenols, while increasing sterol content to 30 mol% resulted in decreased EE. Particle size and PDI increased with sterol content, while liposomes prepared without sterols showed the smallest vesicle size. Encapsulation of the extract led to smaller liposomal diameters and slight increases in PDI values. Zeta potential measurements revealed that sterol incorporation enhanced the surface charge and stability of liposomes, with β-sitosterol showing the most pronounced effect. Stability testing demonstrated minimal changes in size, PDI, and zeta potential during storage. UV irradiation and lyophilization processes did not cause significant polyphenol leakage, although lyophilization slightly increased particle size and PDI. Differential scanning calorimetry revealed that polyphenols and sterols modified the lipid membrane transitions, indicating interactions between extract components and the liposomal bilayer. FT-IR spectra confirmed successful integration of the extract into the liposomes, while UV exposure did not significantly alter the spectral features. Thiobarbituric acid reactive substances (TBARS) assay demonstrated the extract’s efficacy in mitigating lipid peroxidation under UV-induced oxidative stress. In contrast, liposomes enriched with sterols showed enhanced peroxidation. Polyphenol diffusion studies showed that encapsulation significantly delayed release, particularly in sterol-containing liposomes. Release assays in simulated gastric and intestinal fluids confirmed controlled, pH-dependent polyphenol delivery, with slightly better retention in β-sitosterol-enriched systems. These findings support the use of β-sitosterol- and cholesterol-enriched liposomes as stable carriers for polyphenolic compounds from wild thyme extract, as bioactive antioxidants, for food and nutraceutical applications. Full article

The Qinghai–Tibet Plateau, a region susceptible to global change, stores substantial amounts of soil organic carbon (SOC) in its alpine grassland. However, little is known about how SOC is regulated by soil microbial communities, which vary with elevation, mean annual temperature (MAT), and mean annual precipitation (MAP). This study integrates phospholipid fatty acid (PLFA) analysis to simultaneously resolve microbial biomass, community composition, and membrane lipid adaptations along an elevational gradient (2861–5090 m) on the Qinghai–Tibet Plateau. This study found that microbial PLFAs increased significantly with rising MAP, while the relationship with MAT was nonlinear. PLFAs of different microbial groups all had a positive effect on SOC storage. At higher altitudes (characterized by lower MAP and lower MAT), Gram-positive bacteria dominated bacterial communities, and fungi dominated the overall microbial community, highlighting microbial structural adaptations as key regulators of carbon storage. Saturated fatty acids with branches of soil microbial membrane dominated across sites, but their prevalence over unsaturated fatty acids decreased at high elevations. These findings establish a mechanistic link between climate-driven microbial community restructuring and SOC vulnerability on the QTP, providing a predictive framework for carbon–climate feedbacks in alpine systems under global warming. Full article

Choline has been recognized as an essential nutrient involved in various physiological functions critical to human health. Adequate daily intake of choline has been established by the US National Academy of Medicine in 1998, considering choline requirements for different ages, sex differences and physiological states (e.g., pregnancy). By serving as a precursor for acetylcholine and phospholipids, choline is important for cholinergic transmission and the structural integrity of cell membranes. In addition, choline is involved in lipid and cholesterol transport and serves as a methyl donor after oxidation to betaine. Extracellular choline is transported across the cell membrane via various transport systems (high-affinity and low-affinity choline transporters) with distinct features and roles. An adequate dietary intake of choline during pregnancy supports proper fetal development, and throughout life supports brain, liver, and muscle functions, while choline deficiency is linked to disease states like fatty liver. Choline has important roles in neurodevelopment, cognition, liver function, lipid metabolism, and cardiovascular health. While its signaling role has been considered mostly indirect via acetylcholine and phosphatidylcholine which are synthesized from choline, emerging evidence supports a role for choline as an intracellular messenger acting on Sigma-1R, a non-opioid intracellular receptor. These new findings expand the cell signaling repertoire and increase the current understanding of the role of choline while warranting more research to uncover the molecular mechanisms and significance in the context of GPCR signaling, the relevance for physiology and disease states. Full article

Phosphoinositide-binding pleckstrin homology (PH) domains interact with both phospholipids and proteins, often complicating their use as specific lipid biosensors. In this study, we introduced specific mutations into the phosphatidylinositol 3,4,5-trisphosphate (PIP₃)-specific PH domains of protein kinase B (Akt) and general receptor for phosphoinositides 1 (GRP1) that disrupt protein-mediated interactions while preserving lipid binding, in order to enhance biosensor specificity for PIP₃, and evaluated their impact on plasma membrane (PM) localization and lipid-tracking ability. Using bioluminescence resonance energy transfer (BRET) and confocal microscopy, we assessed the localization of PH domains in HEK293A cells under different conditions. While Akt-PH mutants showed minimal deviations from the wild type, GRP1-PH mutants exhibited significantly reduced PM localization both at baseline and after stimulation with epidermal growth factor (EGF), insulin, or vanadate. We further developed tandem mutant GRP1-PH domain constructs to enhance PM PIP₃ avidity. Additionally, our investigation into the influence of ADP ribosylation factor 6 (Arf6) activity on GRP1-PH-based biosensors revealed that while the wild-type sensors were Arf6- dependent, the mutants operated independently of Arf6 activity level. These optimized GRP1-PH constructs provide a refined biosensor system for accurate and selective detection of dynamic PIP₃ signaling, expanding the toolkit for dissecting phosphoinositide-mediated pathways. Full article

Azospirillum is a well-studied genus of plant growth-promoting rhizobacteria (PGPR) and one of the most extensively researched diazotrophs. This genus can colonize rhizosphere soil and enhance plant growth and productivity by supplying essential nutrients to the host. Azospirillum–plant interactions involve multiple mechanisms, including nitrogen fixation, the production of phytohormones (auxins, cytokinins, indole acetic acid (IAA), and gibberellins), plant growth regulators, siderophore production, phosphate solubilization, and the synthesis of various bioactive molecules, such as flavonoids, hydrogen cyanide (HCN), and catalase. Thus, Azospirillum is involved in plant growth and development. The genus Azospirillum also enhances membrane activity by modifying the composition of membrane phospholipids and fatty acids, thereby ensuring membrane fluidity under water deficiency. It promotes the development of adventitious root systems, increases mineral and water uptake, mitigates environmental stressors (both biotic and abiotic), and exhibits antipathogenic activity. Biological nitrogen fixation (BNF) is the primary mechanism of Azospirillum, which is governed by structural nif genes present in all diazotrophic species. Globally, Azospirillum spp. are widely used as inoculants for commercial crop production. It is considered a non-pathogenic bacterium that can be utilized as a biofertilizer for a variety of crops, particularly cereals and grasses such as rice and wheat, which are economically significant for agriculture. Furthermore, Azospirillum spp. influence gene expression pathways in plants, enhancing their resistance to biotic and abiotic stressors. Advances in genomics and transcriptomics have provided new insights into plant-microbe interactions. This review explored the molecular mechanisms underlying the role of Azospirillum spp. in plant growth. Additionally, BNF phytohormone synthesis, root architecture modification for nutrient uptake and stress tolerance, and immobilization for enhanced crop production are also important. A deeper understanding of the molecular basis of Azospirillum in biofertilizer and biostimulant development, as well as genetically engineered and immobilized strains for improved phosphate solubilization and nitrogen fixation, will contribute to sustainable agricultural practices and help to meet global food security demands. Full article

We present a miniaturized, inexpensive, and user-friendly microfluidic platform to support biological applications. The system integrates a mini-incubator providing controlled environmental conditions and housing a microfluidic device for long-term cell culture experiments. The incubator is designed to be compatible with standard inverted optical microscopes and Raman spectrometers, allowing for the non-invasive imaging and spectroscopic analysis of cell cultures in vitro. The microfluidic device, which reproduces a dynamic environment, was optimized to sustain a passive, gravity-driven flow of medium, eliminating the need for an external pumping system and reducing mechanical stress on the cells. The platform was tested using Raman analysis and adherent tumoral cells to assess proliferation prior and subsequent to hydrogen peroxide treatment for oxidative stress induction. The results demonstrated a successful adhesion of cells onto the substrate and their proliferation. Furthermore, the platform is suitable for carrying out optical monitoring of cultures and Raman analysis. In fact, it was possible to discriminate spectra deriving from control and hydrogen peroxide-treated cells in terms of DNA backbone and cellular membrane modification effects provoked by reactive oxygen species (ROS) activity. The 800–1100 cm⁻¹ band highlights the destructive effects of ROS on the DNA backbone’s structure, as its rupture modifies its vibration; moreover, unpaired nucleotides are increased in treated sample, as shown in the 1154–1185 cm⁻¹ band. Protein synthesis deterioration, led by DNA structure damage, is highlighted in the 1257–1341 cm⁻¹, 1440–1450 cm⁻¹, and 1640–1670 cm⁻¹ bands. Furthermore, membrane damage is emphasized in changes in the 1270, 1301, and 1738 cm⁻¹ frequencies, as phospholipid synthesis is accelerated in an attempt to compensate for the membrane damage brought about by the ROS attack. This study highlights the potential use of this platform as an alternative to conventional culturing and analysis procedures, considering that cell culturing, optical imaging, and Raman spectroscopy can be performed simultaneously on living cells with minimal cellular stress and without the need for labeling or fixation. Full article

Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by restricted social communication and repetitive behaviors. Prenatal stress is critical in neurodevelopment and increases risk for ASD, particularly in those with greater genetic susceptibility to stress. Docosahexaenoic acid (DHA) is one of the most abundant ω-3 fatty acids in the membrane phospholipids of the mammalian brain, and dietary DHA plays an important role in brain development and maintenance of brain structure. In this study, we investigated whether peri-natal supplementation of DHA can alleviate autistic-like behaviors in a genetic risk/stress mouse model and how it alters lipid peroxidation activity and GABAergic system gene expression in the forebrain. Pregnant heterozygous serotonin transporter knockout (SERT-KO) and wild-type (WT) dams were placed in either non-stressed control conditions or chronic variable stress (CVS) conditions and fed either a control diet or a DHA-rich (1% by weight) diet. Offspring of each group were assessed for anxiety and autism-associated behavior at post-natal day 60 using an open field test, elevated plus maze test, repetitive behavior, and the 3-chamber social approach test. A liquid chromatography-mass spectrometry (LC-MS)-based method was used to follow changes in levels of lipid peroxidation products in the cerebral cortex. Male offspring of prenatally stressed SERT-het KO dams exhibited decreased social preference behaviors and increased repetitive grooming behaviors compared to WT control offspring. Moreover, DHA supplementation in male SERT-het mice decreased frequency of grooming behaviors albeit showing no associated effects on social behaviors. Regardless of stress conditions, supplementation of DHA to the WT mice did not result in alterations in grooming nor social interaction in the offspring. Furthermore, no apparent changes were observed in the lipid peroxidation products comparing the stressed and non-stressed brains. Gad2 was downregulated in the cortex of female offspring of prenatally stressed SERT-KO dams, and this change appeared to be rescued by DHA supplementation in offspring. Gad2 was upregulated in the striatum of male offspring of prenatally stressed SERT-KO dams, but DHA did not significantly alter the expression compared to the control diet condition. Full article

Helicobacter pylori, which colonizes the human gastric mucosa, uses a cluster of polar, sheathed flagella to swim across the mucous layer of the stomach. The function and biogenesis of the H. pylori flagellar sheath are poorly understood. Cardiolipin is a phospholipid that accumulates in regions of the membrane that have negative curvature, such as the cell pole, cell septum, and flagellar sheath. The final step in cardiolipin biosynthesis is catalyzed by cardiolipin synthase. H. pylori has at least two cardiolipin synthases, one of which is cardiolipin synthase C (ClsC). Bioinformatic analysis revealed that homologs of H. pylori ClsC are restricted to Helicobacter species that have sheathed flagella and the ClsC homologs are predicted lipoproteins. Fluorescence microscopy revealed that a ClsC super-folder green fluorescent protein localized to the cell pole and cell septum in H. pylori G27. Comparing the proteomes of isolated sheathed flagella from the H. pylori B128 wild type and a clsC::cat mutant, we identified five proteins that were absent in the mutant flagellum preparations. One of the proteins was FaaA, an autotransporter that localizes to the flagellar sheath. These findings suggest that the localization of FaaA and possibly other proteins to the flagellar sheath is dependent on ClsC. Full article

The polyunsaturated fatty acids of the omega-3 class have been widely investigated due to their antitumor properties, including in prostate cancer (PCa). Among them is docosahexaenoic acid (DHA, C22:6 ω-3), whose biological activity is higher than other omega-3s, exhibiting a stronger impact on PCa. The specific mechanisms triggered by DHA are blurred by studies that used a blend of omega-3s, delaying the understanding of its biological role, and hence alternative therapeutic approaches. DHA is differentially processed between normal and malignant epithelial PCa cells, which suggests its function as a tumor suppressor. At cell-specific level, it downregulates key pathways in PCa, such as androgen signaling and lipid metabolism, but also changes membrane composition by disrupting phospholipid balance and increasing unsaturation status, arrests the cell cycle, and induces apoptosis and reactive oxygen species (ROS) overproduction. At the tissue level, DHA seems to influence stromal components, such as the inhibition of cancer-associated fibroblast differentiation and resolution of inflammation, which generates a microenvironment favorable to PCa initiation and progression. Considering that such effects are misunderstood and assigned to omega-3s in general, this review aims to discuss the specific effects of DHA on PCa based on in vitro and in vivo evidence. Full article