Botrytis cinerea and Penicillium expansum produce deterioration in fruit quality, causing losses to the food industry. Thus, plant essential oils (EOs) have been proposed as a sustainable alternative ...for minimizing the application of synthetic fungicides due to their broad-spectrum antifungal properties. This study investigated the efficacy of five EOs in suppressing the growth of B. cinerea and P. expansum and their potential antifungal mechanisms. EOs of Mentha × piperita L., Origanum vulgare L., Thymus vulgaris L., Eucalyptus globules Labill., and Lavandula angustifolia Mill., were screened for both fungi. The results showed that the EO of T. vulgaris and O. vulgare were the most efficient in inhibiting the growth of B. cinerea and P. expansum. The concentration increase of all EO tested increased fungi growth inhibition. Exposure of fungi to EOs of T. vulgaris and O. vulgare increased the pH and the release of constituents absorbing 260 nm and soluble proteins, reflecting membrane permeability alterations. Fluorescence microscopic examination revealed that tested EOs produce structural alteration in cell wall component deposition, decreasing the hypha width. Moreover, propidium iodide and Calcein-AM stains evidenced the loss of membrane integrity and reduced cell viability of fungi treated with EOs. Fungi treated with EOs decreased the mitochondria activity and the respiratory process. Therefore, these EOs are effective antifungal agents against B. cinerea and P. expansum, which is attributed to changes in the cell wall structure, the breakdown of the cell membrane, and the alteration of the mitochondrial activity.
•Essential oils (EOs) have antifungal activity against B. cinérea and P. expansum.•EOs promote the release of fungal cell constituents of B. cinérea and P. expansum.•EO of O. vulgare and T. vulgaris altered fungal fluidity of cell membrane.•EO of O. vulgare and T. vulgaris altered the viability of spores and mycelia.•EO produce fungal physiological changes in mitochondria and cell wall of fungi.
Alcoholic liver disease (ALD) has attracted widespread attention because of the ever-increasing alcohol consumption and high morbidity. However, there is still no effective detection method to ...prevent the deterioration of the disease. Cholesterol, as the main component of the cell membrane (CM), often transported to lipid droplets (LDs) for storage in hepatocytes. Meanwhile, abnormal changes of cholesterol could cause liver diseases, such as Tangier disease. Based on cholesterol could serve as a hub that affects the cell membrane fluidity (CMF) and the number of LDs, we planned to study the microscopic changes of CMF and LDs in ALD. As viscous media could limit the intramolecular motion of fluorescent probes, aggregation induced emission luminogens (AIEgens), which typically have rotators and vibrators in their structures and emit strongly in the aggregate state, may be promising candidates for CMF and LD study. So two AIE probes (TPCN and NDPB) were designed and synthesized based on the typical AIE skeleton, tetraphenylethylene (TPE), which could selectively target CMs and LDs, respectively. These probes exhibited high chemical stability, controllable emission, and excellent subcellular specificity. They successfully sensed the correlated changes of CMs and LDs in ALD model, which would contribute to understanding the microscopic process of ALD pathogenesis and further development of ALD therapeutic drugs.
Two AIE probes (TPCN and NDPB) was developed with excellent organelle targeting ability and applied to monitor microscopic changes of cell membrane fluidity (CMF) and lipid droplets (LDs) in alcoholic liver disease (ALD) by fluorescence imaging. It was proven that there was a close relationship between the dynamic changes of CMF and intracellular LDs, which may help to understand the pathogenesis of ALD. Display omitted
•Two AIE probes (TPCN and NDPB) was designed and synthesized based on the typical AIE skeleton, tetraphenylethylene (TPE).•Highly specific to cell membrane and lipid droplets (LDs) in dual channels.•Monitoring microscopic change of cell membrane fluidity (CMF) and LDs in alcoholic liver disease (ALD) cell models.•AIE probes with fluorescence intensity correlated to the change of CMF and LDs in ALD.•Fluorescence imaging with TPCN allowed the diagnosis of ALD mouse models in vivo.
It has long been established that hyperthermia increases the therapeutic benefit of radiation and chemotherapy in cancer treatment. During the last few years there have been substantial technical ...improvements in the sources used to apply and measure heat, which greatly increases enthusiasm for the clinical use of hyperthermia. These advances are converging with a better understanding of the physiological and molecular effects of hyperthermia. Therefore, we are now at a juncture where the parameters that will influence the efficacy of hyperthermia in cancer treatment can be optimised in a more systematic and rational manner. In addition, the novel insights in hyperthermia's many biological effects on tumour cells will ultimately result in new treatment regimes. For example, the molecular effects of hyperthermia on the essential cellular process of DNA repair suggest novel combination therapies, with DNA damage response targeting drugs that should now be clinically explored. Here, we provide an overview of recent studies on the various macroscopic and microscopic biological effects of hyperthermia. We indicate the significance of these effects on current treatments and suggest how they will help design novel future treatments.
Oxidative stress mediated by reactive oxygen species (ROS) is a key process for adverse aerosol health effects. Secondary organic aerosols (SOA) account for a major fraction of fine particulate ...matter, and their inhalation and deposition into the respiratory tract causes the formation of ROS by chemical and cellular processes, but their relative contributions are hardly quantified and their link to oxidative stress remains uncertain. Here, we quantified cellular and chemical superoxide generation by 9,10-phenanthrenequinone (PQN) and isoprene SOA using a chemiluminescence assay combined with electron paramagnetic resonance spectroscopy as well as kinetic modeling. We also applied cellular imaging techniques to study the cellular mechanism of superoxide release and oxidative damage on cell membranes. We show that PQN and isoprene SOA activate NADPH oxidase in macrophages to release massive amounts of superoxide, overwhelming the superoxide formation by aqueous chemical reactions in the epithelial lining fluid. The activation dose for PQN is 2 orders of magnitude lower than that of isoprene SOA, suggesting that quinones are more toxic. While higher exposures trigger cellular antioxidant response elements, the released ROS induce oxidative damage to the cell membrane through lipid peroxidation. Such mechanistic and quantitative understandings provide a basis for further elucidation of adverse health effects and oxidative stress by fine particulate matter.
Understanding the vibrational information encoded within the terahertz (THz) spectrum of biomolecules is critical for guiding the exploration of its functional responses to specific THz radiation ...wavelengths. This study investigated several important phospholipid components of biological membranes-distearoyl phosphatidylethanolamine (DSPE), dipalmitoyl phosphatidylcholine (DPPC), sphingosine phosphorylcholine (SPH), and lecithin bilayer-using THz time-domain spectroscopy. We observed similar spectral patterns for DPPC, SPH, and the lecithin bilayer, all of which contain the choline group as the hydrophilic head. Notably, the spectrum of DSPE, which has an ethanolamine head group, was different. Interestingly, density functional theory calculations confirmed that the absorption peak common to DSPE and DPPC at approximately 3.0 THz originated from a collective vibration of their similar hydrophobic tails. Accordingly, the cell membrane fluidity of RAW264.7 macrophages with irradiation at 3.1 THz was significantly enhanced, leading to improved phagocytosis. Our results highlight the importance of the spectral characteristics of the phospholipid bilayers when studying their functional responses in the THz band and suggest that irradiation at 3.1 THz is a potential non-invasive strategy to increase the fluidity of phospholipid bilayers for biomedical applications such as immune activation or drug administration.
Lactobacilli convert linoleic acid to the antifungal compound 10-hydroxy-12-octadecenoic acid (10-HOE) by linoleate 10-hydratase (10-LAH). However, the effect of this conversion on cellular membrane ...physiology and properties of the cell surface have not been demonstrated. Moreover,
produces 13-hydroxy-9-octadecenoic acid (13-HOE) in addition to 10-HOE, but the antifungal activity of 13-HOE was unknown. Phylogenetic analyses conducted in this study did not differentiate between 10-LAH and linoleate 13-hydratase (13-LAH). Thus, linoleate hydratases (LAHs) must be characterized through their differences in their activities of linoleate conversion. Four genes encoding putative LAHs from lactobacilli were cloned, heterologous expressed, purified and identified as FAD-dependent 10-LAH. The unsaturated fatty acid substrates stimulated the growth of lactobacilli. We also investigated the role of 10-LAH in ethanol tolerance, membrane fluidity and hydrophobicity of cell surfaces in lactobacilli by disruption of
. Compared with the
deficient strain, 10-LAH in wild-type strain did not exert effect on cell survival and membrane fluidity under ethanol stress, but influenced the cell surface hydrophobicity. Moreover, deletion of 10-LAH in
facilitated purification of 13-HOE and demonstration of its antifungal activity against
and
.
Human skin is the body's largest organ that protects against diverse environmental injuries. However, ultraviolet (UV) radiation, which induces a transient increase in the intracellular level of ...reactive oxygen species (ROS) and leads to a variety of injuries and various skin diseases, has deleterious effects on living organisms. Quercetin is a naturally occurring compound with strong antioxidant action and can successfully scavenge free radicals. In the present study, we investigated the effects and the mechanism of quercetin on UVB‑induced cytotoxicity in keratinocyte (HaCaT) cells. The results of this study showed that quercetin (20 μM) significantly blocked UVB irradiation (15 mJ/cm2)‑induced intracellular ROS generation. In addition, the ROS clearing ability of quercetin prevented cell membrane and mitochondria from ROS attack and inhibited cell membrane fluidity decrease and mitochondrial membrane depolarization. Moreover, the outflow of cytochrome c and apoptosis were markedly inhibited. These results suggest that the protective effect of quercetin against UVB irradiation‑induced toxicity is mainly mediated by the ROS scavenging ability. Thus, quercetin is a potential agent against UVB irradiation‑induced skin damage.
Plant foods contain various flavonoids with nutraceutical and health benefits. Structurally different flavonoids were compared by the potency to interact with liposomal membranes in the context of ...their mode of action. A series of fluorescence polarisation measurements showed that flavonoids (1–10
μM) structure-dependently acted on the deeper regions of lipid bilayers to decrease membrane fluidity. Their comparative effects on cell-mimetic membranes, consisting of unsaturated phospholipids and cholesterol, characterised the structure–membrane interactivity relationship: 3-hydroxylation of the C ring, non-modification of the B ring and 5,7-dihydroxylation of the A ring led to the greatest membrane interactivity, followed by 3′,4′-dihydroxylation of the B ring. Galangin and quercetin, meeting such a structural requirement, inhibited the proliferation of tumour cells at 10–100
μM, together with rigidifying cell membranes, but not membrane-inactive flavonoids. The structure-dependent membrane interaction, which modifies the fluidity, is mechanistically associated with flavonoid bioactivity in a membranous lipid phase.
There are a large number of active cold-adapted microorganisms in the perennial cold environment. Due to their high-efficiency and energy-saving catalytic properties, cold-adapted microorganisms have ...become valuable natural resources with potential in various biological fields. In this study, a series of cold response strategies for microorganisms were summarized. This mainly involves the regulation of cell membrane fluidity, synthesis of cold adaptation proteins, regulators and metabolic changes, energy supply, and reactive oxygen species. Also, the potential of biocatalysts produced by cold-adapted microorganisms including cold-active enzymes, ice-binding proteins, polyhydroxyalkanoates, and surfactants was introduced, which provided a guidance for expanding its application values. Overall, new insights were obtained on response strategies of microorganisms to cold environments in this review. This will deepen the understanding of the cold tolerance mechanism of cold-adapted microorganisms, thus promoting the establishment and application of low-temperature biotechnology.
Synovial mesenchymal stem cells (MSCs) have high freeze-thaw tolerance, whereas human umbilical vein endothelial cells (HUVECs) have low freezing tolerance. The differences in cell type-specific ...freeze-thaw tolerance and the mechanisms involved are unclear. This study thus aimed to identify the biological and physical factors involved in the differences in freeze-thaw tolerance between MSCs and HUVECs.
For biological analysis, MSC and HUVEC viability after freeze-thawing and alteration of gene expression in response to dimethyl sulfoxide (DMSO, a cryoprotectant) were quantitatively evaluated. For physical analysis, the cell membrane fluidity of MSCs and HUVECs before and after DMSO addition was assessed using a histogram for generalized polarization frequency.
HUVECs showed lower live cell rates and higher gene expression alteration related to extracellular vesicles in response to DMSO than MSCs. Fluidity measurements revealed that the HUVEC membrane was highly fluidic and sensitive to DMSO compared to that of MSCs. Addition of CAY10566, an inhibitor of stearoyl-coA desaturase (SCD1) that produces highly fluidic desaturated fatty acids, decreased the fluidity of HUVECs and increased their tolerance to DMSO. The combination of CAY10566 and antioxidant glutathione (GSH) treatment improved HUVEC viability from 57 to 69%. Membrane fluidity alteration may thus contribute to pore-induced DMSO influx into the cytoplasm and reactive oxygen species production, leading to greater cytotoxicity in HUVECs, which have low antioxidant capacity.
Differences in freeze-thaw tolerance originate from differences in the cell membranes with respect to fluidity and antioxidant capacity. These findings provide a basis for analyzing cell biology and membrane-physics to establish appropriate long-term preservation methods aimed at promoting transplantation therapies.
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