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Biosensors Jun 2024The overall 5-year survival rate of ovarian cancer (OC) is generally low as the disease is often diagnosed at an advanced stage of progression. To save lives, OC must be...
The overall 5-year survival rate of ovarian cancer (OC) is generally low as the disease is often diagnosed at an advanced stage of progression. To save lives, OC must be identified in its early stages when treatment is most effective. Early-stage OC causes the upregulation of lysophosphatidic acid (LPA), making the molecule a promising biomarker for early-stage detection. An LPA assay can additionally stage the disease since LPA levels increase with OC progression. This work presents two methods that demonstrate the prospective application for detecting LPA: the electromagnetic piezoelectric acoustic sensor (EMPAS) and a chemiluminescence-based iron oxide nanoparticle (IONP) approach. Both methods incorporate the protein complex gelsolin-actin, which enables testing for detection of the biomarker as the binding of LPA to the complex results in the separation of gelsolin from actin. The EMPAS was characterized with contact angle goniometry and atomic force microscopy, while gelsolin-actin-functionalized IONPs were characterized with transmission electron microscopy and Fourier transform infrared spectroscopy. In addition to characterization, LPA detection was demonstrated as a proof-of-concept in Milli-Q water, buffer, or human serum, highlighting various LPA assays that can be developed for the early-stage detection of OC.
Topics: Lysophospholipids; Humans; Female; Ovarian Neoplasms; Biomarkers, Tumor; Biosensing Techniques; Gelsolin; Actins; Early Detection of Cancer
PubMed: 38920591
DOI: 10.3390/bios14060287 -
Biosensors May 2024Biosensors play an important role in numerous research fields. Quartz crystal microbalances with dissipation monitoring (QCM-Ds) are sensitive devices, and binding...
Biosensors play an important role in numerous research fields. Quartz crystal microbalances with dissipation monitoring (QCM-Ds) are sensitive devices, and binding events can be observed in real-time. In combination with aptamers, they have great potential for selective and label-free detection of various targets. In this study, an alternative surface functionalization for a QCM-D-based aptasensor was developed, which mimics an artificial cell membrane and thus creates a physiologically close environment for the binding of the target to the sensor. Vesicle spreading was used to form a supported lipid bilayer (SLB) of 1-palmitoyl-2-oleoyl-glycero-3-phosphocholine (POPC) and 1,2-dipalmitoyl-sn-glycero-3-phosphethanolamine-N-(cap biotinyl) (biotin-PE). The SLB was then coated with streptavidin followed by applying a biotinylated aptamer against thrombin. SLB formation was investigated in terms of temperature and composition. Temperatures of 25 °C and below led to incomplete SLB formation, whereas a full bilayer was built at higher temperatures. We observed only a small influence of the content of biotinylated lipids in the mixture on the further binding of streptavidin. The functionalization of the sensor surface with the thrombin aptamer and the subsequent thrombin binding were investigated at different concentrations. The sensor could be reconstituted by incubation with a 5 M urea solution, which resulted in the release of the thrombin from the sensor surface. Thereafter, it was possible to rebind thrombin. Thrombin in spiked samples of human serum was successfully detected. The developed system can be easily applied to other target analytes using the desired aptamers.
Topics: Biosensing Techniques; Thrombin; Lipid Bilayers; Quartz Crystal Microbalance Techniques; Aptamers, Nucleotide; Humans; Phosphatidylcholines
PubMed: 38920574
DOI: 10.3390/bios14060270 -
Plant Physiology Jun 2024Pollen germination and pollen tube elongation require rapid phospholipid production and remodeling in membrane systems that involve both de novo synthesis and turnover....
Pollen germination and pollen tube elongation require rapid phospholipid production and remodeling in membrane systems that involve both de novo synthesis and turnover. Phosphatidic acid phosphohydrolase (PAH) and lysophosphatidylcholine acyltransferase (LPCAT) are two key enzymes in membrane lipid maintenance. PAH generates diacylglycerol (DAG), a necessary precursor for the de novo synthesis of phosphatidylcholine (PC), while LPCAT reacylates lysophosphatidylcholine (LPC) to PC and plays an essential role in the remodeling of membrane lipids. In this study, we investigated the synthetic defects of pah and lpcat mutations in sexual reproduction of Arabidopsis (Arabidopsis thaliana) and explored the prospect of pistil lipid provision to pollen tube growth. The combined deficiencies of lpcat and pah led to decreased pollen tube growth in the pistil and reduced male transmission. Interestingly, pistils of the lipid mutant dgat1 ameliorated the male transmission deficiencies of pah lpcat pollen. In contrast, pollination with a non-specific phospholipase C (NPC) mutant exacerbated the fertilization impairment of the pah lpcat pollen. Given the importance of DAG in lipid metabolism and its contrasting changes in the dgat1 and npc mutants, we further investigated whether DAG supplement in synthetic media could influence pollen performance. DAG was incorporated into phospholipids of germinating pollen and stimulated pollen tube growth. Our study provides evidence that pistil derived lipids contribute to membrane lipid synthesis in pollen tube growth, a hitherto unknown role in synergistic pollen-pistil interactions.
PubMed: 38917229
DOI: 10.1093/plphys/kiae276 -
Lipids in Health and Disease Jun 2024Observational studies have indicated that the plasma lipid profiles of patients with atopic dermatitis show significant differences compared to healthy individuals....
BACKGROUND
Observational studies have indicated that the plasma lipid profiles of patients with atopic dermatitis show significant differences compared to healthy individuals. However, the causal relationship between these differences remains unclear due to the inherent limitations of observational studies. Our objective was to explore the causal effects between 179 plasma lipid species and atopic dermatitis, and to investigate whether circulating inflammatory proteins serve as mediators in this causal pathway.
METHODS
We utilized public genome-wide association studies data to perform a bidirectional two-sample, two-step mendelian randomization study. The inverse variance-weighted method was adopted as the primary analysis technique. MR-Egger and the weighted median were used as supplementary analysis methods. MR-PRESSO, Cochran's Q test, and MR-Egger intercept test were applied for sensitivity analyses to ensure the robustness of our findings.
RESULTS
The Mendelian randomization analysis revealed that levels of Phosphatidylcholine (PC) (18:1_20:4) (OR: 0.950, 95% CI: 0.929-0.972, p = 6.65 × 10), Phosphatidylethanolamine (O-18:1_20:4) (OR: 0.938, 95% CI: 0.906-0.971, p = 2.79 × 10), Triacylglycerol (TAG) (56:6) (OR: 0.937, 95% CI: 0.906-0.969, p = 1.48 × 10) and TAG (56:8) (OR: 0.918, 95% CI: 0.876-0.961, p = 2.72 × 10) were inversely correlated with the risk of atopic dermatitis. Conversely, PC (18:1_20:2) (OR: 1.053, 95% CI: 1.028-1.079, p = 2.11 × 10) and PC (O-18:1_20:3) (OR: 1.086, 95% CI: 1.039-1.135, p = 2.47 × 10) were positively correlated with the risk of atopic dermatitis. The results of the reverse directional Mendelian randomization analysis indicated that atopic dermatitis exerted no significant causal influence on 179 plasma lipid species. The level of circulating IL-18R1 was identified as a mediator for the increased risk of atopic dermatitis associated with higher levels of PC (18:1_20:2), accounting for a mediation proportion of 9.07%.
CONCLUSION
Our research suggests that plasma lipids can affect circulating inflammatory proteins and may serve as one of the pathogenic factors for atopic dermatitis. Targeting plasma lipid levels as a treatment for atopic dermatitis presents a potentially novel approach.
Topics: Dermatitis, Atopic; Humans; Mendelian Randomization Analysis; Genome-Wide Association Study; Lipids; Triglycerides; Phosphatidylethanolamines; Phosphatidylcholines; Polymorphism, Single Nucleotide
PubMed: 38909247
DOI: 10.1186/s12944-024-02134-9 -
Lipids in Health and Disease Jun 2024Lipid droplet (LD)-laden microglia is a key pathological hallmark of multiple sclerosis. The recent discovery of this novel microglial subtype,...
BACKGROUND
Lipid droplet (LD)-laden microglia is a key pathological hallmark of multiple sclerosis. The recent discovery of this novel microglial subtype, lipid-droplet-accumulating microglia (LDAM), is notable for increased inflammatory factor secretion and diminished phagocytic capability. Lipophagy, the autophagy-mediated selective degradation of LDs, plays a critical role in this context. This study investigated the involvement of microRNAs (miRNAs) in lipophagy during demyelinating diseases, assessed their capacity to modulate LDAM subtypes, and elucidated the potential underlying mechanisms involved.
METHODS
C57BL/6 mice were used for in vivo experiments. Two weeks post demyelination induction at cervical level 4 (C4), histological assessments and confocal imaging were performed to examine LD accumulation in microglia within the lesion site. Autophagic changes were observed using transmission electron microscopy. miRNA and mRNA multi-omics analyses identified differentially expressed miRNAs and mRNAs under demyelinating conditions and the related autophagy target genes. The role of miR-223 in lipophagy under these conditions was specifically explored. In vitro studies, including miR-223 upregulation in BV2 cells via lentiviral infection, validated the bioinformatics findings. Immunofluorescence staining was used to measure LD accumulation, autophagy levels, target gene expression, and inflammatory mediator levels to elucidate the mechanisms of action of miR-223 in LDAM.
RESULTS
Oil Red O staining and confocal imaging revealed substantial LD accumulation in the demyelinated spinal cord. Transmission electron microscopy revealed increased numbers of autophagic vacuoles at the injury site. Multi-omics analysis revealed miR-223 as a crucial regulatory gene in lipophagy during demyelination. It was identified that cathepsin B (CTSB) targets miR-223 in autophagy to integrate miRNA, mRNA, and autophagy gene databases. In vitro, miR-223 upregulation suppressed CTSB expression in BV2 cells, augmented autophagy, alleviated LD accumulation, and decreased the expression of the inflammatory mediator IL-1β.
CONCLUSION
These findings indicate that miR-223 plays a pivotal role in lipophagy under demyelinating conditions. By inhibiting CTSB, miR-223 promotes selective LD degradation, thereby reducing the lipid burden and inflammatory phenotype in LDAM. This study broadens the understanding of the molecular mechanisms of lipophagy and proposes lipophagy induction as a potential therapeutic approach to mitigate inflammatory responses in demyelinating diseases.
Topics: Animals; MicroRNAs; Microglia; Mice; Autophagy; Lipid Droplets; Mice, Inbred C57BL; Demyelinating Diseases; Cathepsin B; Lysophosphatidylcholines; Disease Models, Animal; Male; Gene Expression Regulation; Cell Line
PubMed: 38909243
DOI: 10.1186/s12944-024-02185-y -
Trends in Biochemical Sciences Jun 2024Phosphatidic acid (PA) is involved in biotic and abiotic stress responses in plants. Here, we summarize quantitative lipidomics and real-time imaging used in PA studies...
Phosphatidic acid (PA) is involved in biotic and abiotic stress responses in plants. Here, we summarize quantitative lipidomics and real-time imaging used in PA studies and highlight recent studies of diacylglycerol (DAG) kinase (DGK) 5, an enzyme involved in PA biosynthesis, facilitating fine-tuning PA production for optimal stress responses in plants.
PubMed: 38908926
DOI: 10.1016/j.tibs.2024.05.008 -
Life Science Alliance Sep 2024H3.1 histone is predominantly synthesized and enters the nucleus during the G1/S phase of the cell cycle, as a new component of duplicating nucleosomes. Here, we found...
H3.1 histone is predominantly synthesized and enters the nucleus during the G1/S phase of the cell cycle, as a new component of duplicating nucleosomes. Here, we found that p53 is necessary to secure the normal behavior and modification of H3.1 in the nucleus during the G1/S phase, in which p53 increases C-terminal domain nuclear envelope phosphatase 1 (CTDNEP1) levels and decreases enhancer of zeste homolog 2 (EZH2) levels in the H3.1 interactome. In the absence of p53, H3.1 molecules tended to be tethered at or near the nuclear envelope (NE), where they were predominantly trimethylated at lysine 27 (H3K27me3) by EZH2, without forming nucleosomes. This accumulation was likely caused by the high affinity of H3.1 toward phosphatidic acid (PA). p53 reduced nuclear PA levels by increasing levels of CTDNEP1, which activates lipin to convert PA into diacylglycerol. We moreover found that the cytosolic H3 chaperone HSC70 attenuates the H3.1-PA interaction, and our molecular imaging analyses suggested that H3.1 may be anchored around the NE after their nuclear entry. Our results expand our knowledge of p53 function in regulation of the nuclear behavior of H3.1 during the G1/S phase, in which p53 may primarily target nuclear PA and EZH2.
Topics: Histones; Tumor Suppressor Protein p53; Cell Nucleus; Humans; Enhancer of Zeste Homolog 2 Protein; G1 Phase; S Phase; Nuclear Envelope; Methylation; Animals; Nucleosomes
PubMed: 38906678
DOI: 10.26508/lsa.202402835 -
Journal of Molecular Modeling Jun 2024Electroporation is a technique that creates electrically generated pores in the cell membrane by modifying transmembrane potential. In this work, the finite element...
CONTEXT
Electroporation is a technique that creates electrically generated pores in the cell membrane by modifying transmembrane potential. In this work, the finite element method (FEM) was used to examine the induced transmembrane voltage (ITV) of a spherical-shaped MCF-7 cell, allowing researchers to determine the stationary ITV. A greater ITV than the critical value causes permeabilization of the membrane. Furthermore, the present study shows how a specific surface conductivity can act as a stand-in for the thin layer that constitutes a cell membrane as the barrier between extracellular and intracellular environments. Additionally, the distribution of ITV on the cell membrane and its maximum value were experimentally evaluated for a range of applied electric fields. Consequently, the entire cell surface area was electroporated 66% and 68% for molecular dynamics (MD) simulations and FEM, respectively, when the external electric field of 1500 V/cm was applied to the cell suspension using the previously indicated numerical methods. Furthermore, the lipid bilayers' molecular structure was changed, which led to the development of hydrophilic holes with a radius of 1.33 nm. Applying MD and FEM yielded threshold values for transmembrane voltage of 700 and 739 mV, respectively.
METHOD
Using MD simulations of palmitoyloleoyl-phosphatidylcholine (POPC), pores in cell membranes exposed to external electric fields were numerically investigated. The dependence on the electric field was estimated and developed, and the amount of the electroporated cell surface area matches the applied external electric field. To investigate more, a mathematical model based on an adaptive neuro-fuzzy inference system (ANFIS) is employed to predict the percent cell viability of cancerous cells after applying four pulses during electroporation. For MD simulations, ArgusLab, VMD, and GROMACS software packages were used. Moreover, for FEM analysis, COMSOL software package was used. Also, it is worth mentioning that for mathematical model, MATLAB software is used.
Topics: Molecular Dynamics Simulation; Humans; Cell Membrane; Electroporation; Finite Element Analysis; Lipid Bilayers; Membrane Potentials; MCF-7 Cells; Electricity; Cell Membrane Permeability; Phosphatidylcholines
PubMed: 38904863
DOI: 10.1007/s00894-024-06012-0 -
International Journal of Systematic and... Jun 2024Two Gram-stain-negative, rod-shaped, non-motile, strictly aerobic strains, forming yellow colonies and designated F6058 and S2608, were isolated from marine sediment...
Two Gram-stain-negative, rod-shaped, non-motile, strictly aerobic strains, forming yellow colonies and designated F6058 and S2608, were isolated from marine sediment collected in Weihai, PR China. Both strains grow at 4-40 °C (optimum, 30-33 °C), pH 6.0-7.5 (optimum, pH 6.5) and in the presence of 0-7.0 % (w/v) NaCl. The optimum NaCl concentrations for strains F6058 and S2608 were 2.0 % and 2.5 %, respectively. Phylogenetic analysis of the 16S rRNA gene sequences indicated that strains F6058 and S2608 share an evolutionary lineage with members of the genus . The isolates exhibited a 16S rRNA gene sequence similarity of 96.7 % to each other. Strains F6058 exhibited the highest 16S rRNA gene sequence similarity to F64183 (98.8 %), and S2608 was most similar to A71 (96.9 %). Iso-C, anteiso-C and iso-C 3-OH were the major fatty acids of strains F6058 and S2608. The sole respiratory quinone of both isolates was menaquinone 6 (MK-6). The polar lipid profiles of the isolates both consisted of phosphatidylethanolamine and phosphoglycolipids; however, strain F6058 exhibited one glycolipid, one aminolipid and two unidentified polar lipids, and strain S2608 also had two glycolipids and one unidentified polar lipid. The DNA G+C contents of strains F6058 and S2608 were 34.6 % and 37.7 mol%, respectively. Based on their phenotypic, chemotaxonomic and genomic characteristics, strains F6058 and S2608 were considered to represent novel species of the genus , for which the names sp. nov. and sp. nov. were proposed. The type strains are F6058 (=KCTC 92653=MCCC 1H01358) and S2608 (KCTC 92652=MCCC 1H01361).
Topics: RNA, Ribosomal, 16S; Geologic Sediments; Phylogeny; Fatty Acids; China; Base Composition; Vitamin K 2; Bacterial Typing Techniques; DNA, Bacterial; Sequence Analysis, DNA; Seawater; Molecular Sequence Data; Phospholipids; Phosphatidylethanolamines
PubMed: 38904664
DOI: 10.1099/ijsem.0.006423 -
Frontiers in Endocrinology 2024Polycystic ovary syndrome with insulin resistance (PCOS-IR) is the most common endocrine and metabolic disease in women of reproductive age, and low fertility in PCOS...
High coverage of targeted lipidomics revealed lipid changes in the follicular fluid of patients with insulin-resistant polycystic ovary syndrome and a positive correlation between plasmalogens and oocyte quality.
BACKGROUND
Polycystic ovary syndrome with insulin resistance (PCOS-IR) is the most common endocrine and metabolic disease in women of reproductive age, and low fertility in PCOS patients may be associated with oocyte quality; however, the molecular mechanism through which PCOS-IR affects oocyte quality remains unknown.
METHODS
A total of 22 women with PCOS-IR and 23 women without polycystic ovary syndrome (control) who underwent fertilization and embryo transfer were recruited, and clinical information pertaining to oocyte quality was analyzed. Lipid components of follicular fluid (FF) were detected using high-coverage targeted lipidomics, which identified 344 lipid species belonging to 19 lipid classes. The exact lipid species associated with oocyte quality were identified.
RESULTS
The number (rate) of two pronuclear (2PN) zygotes, the number (rate) of 2PN cleaved embryos, and the number of high-quality embryos were significantly lower in the PCOS-IR group. A total of 19 individual lipid classes and 344 lipid species were identified and quantified. The concentrations of the 19 lipid species in the normal follicular fluid (control) ranged between 10 mol/L and 10 mol/L. In addition, 39 lipid species were significantly reduced in the PCOS-IR group, among which plasmalogens were positively correlated with oocyte quality.
CONCLUSIONS
This study measured the levels of various lipids in follicular fluid, identified a significantly altered lipid profile in the FF of PCOS-IR patients, and established a correlation between poor oocyte quality and plasmalogens in PCOS-IR patients. These findings have contributed to the development of plasmalogen replacement therapy to enhance oocyte quality and have improved culture medium formulations for oocyte maturation (IVM).
Topics: Humans; Female; Polycystic Ovary Syndrome; Follicular Fluid; Oocytes; Adult; Lipidomics; Insulin Resistance; Plasmalogens; Fertilization in Vitro; Lipids; Infertility, Female; Lipid Metabolism; Embryo Transfer; Case-Control Studies
PubMed: 38904043
DOI: 10.3389/fendo.2024.1414289