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Stem Cells and Development Jun 2022Lowest observable adverse effects level (LOAEL) is a standard point-of-departure dose in toxicology. However, first observable adverse effects level (FOAEL) was recently...
Using Live Imaging and Fluorescence Ubiquitinated Cell Cycle Indicator Embryonic Stem Cells to Distinguish G1 Cell Cycle Delays for General Stressors like Perfluoro-Octanoic Acid and Hyperosmotic Sorbitol or G2 Cell Cycle Delay for Mutagenic Stressors like Benzo(a)pyrene.
Lowest observable adverse effects level (LOAEL) is a standard point-of-departure dose in toxicology. However, first observable adverse effects level (FOAEL) was recently reported and is used, in this study, as one criterion to detect a mutagenic stimulus in a live imager. Fluorescence ubiquitinated cell cycle indicator (FUCCI) embryonic stem cells (ESC) are green in the S-G2-M phase of the cell cycle and not green in G1-phase. Standard media change here is a mild stress that delays G1-phase and media change increases green 2.5- to 5-fold. Since stress is mild, media change rapidly increases green cell number, but higher stresses of environmental toxicants and positive control hyperosmotic stress suppress increased green after media change. Perfluoro-octanoic acid (PFOA) and diethyl phthalate (DEP) previously suppressed progression of nongreen to green cell cycle progression. Here, bisphenol A (BPA), cortisol, and positive control hyperosmotic sorbitol also suppress green fluorescence, but benzo(a)pyrene (BaP) at high doses (10 μM) increases green fluorescence throughout the 74-h exposure. Since any stress can affect many cell cycle phases, messenger RNA (mRNA) markers are best interpreted in ratios as dose-dependent mutagens increase in G2/G1 and nonmutagens increase G1/G2. After 74-h exposure, RNAseq detects G1 and G2 markers and increasing BaP doses increase G2/G1 ratios but increasing hyperosmotic sorbitol and PFOA doses increase G1/G2 marker ratios. BaP causes rapid green increase in FOAEL at 2 h of stimulus, whereas retinoic acid caused significant green fluorescence increases only late in culture. Using a live imager to establish FOAEL and G2 delay with FUCCI ESC is a new method to allow commercial and basic developmental biologists to detect drugs and environmental stimuli that are mutagenic. Furthermore, it can be used to test compounds that prevent mutations. In longitudinal studies, uniquely provided by this viable reporter and live imager protocol, follow-up can be done to test whether the preventative compound itself causes harm.
Topics: Benzo(a)pyrene; Caprylates; Cell Cycle; Cell Division; Embryonic Stem Cells; Fluorescence; Mutagens; Sorbitol
PubMed: 35678645
DOI: 10.1089/scd.2021.0330 -
Journal of Biotechnology Jul 2016The present proof-of-concept study reports the construction of a whole-cell biocatalyst for the de novo production of ω-hydroxy octanoic acid. This was achieved by...
The present proof-of-concept study reports the construction of a whole-cell biocatalyst for the de novo production of ω-hydroxy octanoic acid. This was achieved by hijacking the natural fatty acid cycle and subsequent hydroxylation using a specific monooxygenase without the need for the additional feed of alkene-like precursors. For this, we used the model organism Escherichia coli and increased primarily the release of the octanoic acid precursors by overexpressing the plant thioesterase FatB2 from Cuphea hookeriana in a β-oxidation deficient strain, which lead to the production of 2.32mM (8.38mggcww(-1)) octanoic acid in 24h. In order to produce the corresponding ω-hydroxy derivative, we additionally expressed the engineered self-sufficient monooxygenase fusion protein CYP153AMaq(G307A)-CPRBM3 within the octanoic acid producing strain. With this, we finally produced 234μM (0.95mggcww(-1)) ω-hydroxy octanoic acid in a 20h fed-batch set-up.
Topics: Bioreactors; Caprylates; Cuphea; Escherichia coli; Plant Proteins; Thiolester Hydrolases
PubMed: 27184430
DOI: 10.1016/j.jbiotec.2016.05.017 -
Langmuir : the ACS Journal of Surfaces... Dec 2021A profound understanding of the properties of unmodified and saturated fatty acid-modified calcite surfaces is essential for elucidating their resistance and stability...
A profound understanding of the properties of unmodified and saturated fatty acid-modified calcite surfaces is essential for elucidating their resistance and stability in the presence of water droplets. Additional insights can be obtained by also studying the effects of carboxylic acid-saturated aqueous solutions. We elucidate surface wettability, structure, and nanomechanical properties beneath and at the edge of a deposited droplet after its evaporation. When calcite was coated by a highly packed monolayer of stearic acid, a hydrophilic region was found at the three-phase contact line. In atomic force microscopy mapping, this region is characterized by low adhesion and a topographical hillock. The surface that previously was covered by the droplet demonstrated a patchy structure of about 6 nm height, implying stearic acid reorganization into a patchy bilayer-like structure. Our data suggest that during droplet reverse dispensing and droplet evaporation, pinning of the three-phase contact line leads to the transport of dissolved fatty carboxylic acid and possibly calcium bicarbonate Ca(HCO) molecules to the contact line boundary. Compared to the surface of intrinsically hydrophobic materials, such as polystyrene, the changes in contact angle and base diameter during droplet evaporation on stearic acid-modified calcite are strikingly different. This difference is due to stearic acid reorganization on the surface and transport to the water-air interface of the droplet. An effect of the evaporating droplet is also observed on unmodified calcite due to dissolution and recrystallization of the calcite surface in the presence of water. In the case where a water droplet saturated with octanoic acid is used instead of water, the stearic acid-coated calcite remains considerably more stable. Our findings are discussed in terms of the coffee-ring effect.
Topics: Calcium Carbonate; Caprylates; Fatty Acids; Surface Properties; Water
PubMed: 34793681
DOI: 10.1021/acs.langmuir.1c02387 -
Frontiers in Bioengineering and... 2021Production of medium chain-length poly(3-hydroxyalkanoates) [PHA] polymers with tightly defined compositions is an important area of research to expand the application...
Production of medium chain-length poly(3-hydroxyalkanoates) [PHA] polymers with tightly defined compositions is an important area of research to expand the application and improve the properties of these promising biobased and biodegradable materials. PHA polymers with homopolymeric or defined compositions exhibit attractive material properties such as increased flexibility and elasticity relative to poly(3-hydroxybutyrate) [PHB]; however, these polymers are difficult to biosynthesize in native PHA-producing organisms, and there is a paucity of research toward developing high-density cultivation methods while retaining compositional control. In this study, we developed and optimized a fed-batch fermentation process in a stirred tank reactor, beginning with the biosynthesis of poly(3-hydroxydecanoate) [PHD] from decanoic acid by β-oxidation deficient recombinant LSBJ using glucose as a co-substrate solely for growth. Bacteria were cultured in two stages, a biomass accumulation stage (37°C, pH 7.0) with glucose as the primary carbon source and a PHA biosynthesis stage (30°C, pH 8.0) with co-feeding of glucose and a fatty acid. Through iterative optimizations of semi-defined media composition and glucose feed rate, 6.0 g of decanoic acid was converted to PHD with an 87.5% molar yield (4.54 g L). Stepwise increases in the amount of decanoic acid fed during the fermentation correlated with an increase in PHD, resulting in a final decanoic acid feed of 25 g converted to PHD at a yield of 89.4% (20.1 g L, 0.42 g L h), at which point foaming became uncontrollable. Hexanoic acid, octanoic acid, 10-undecenoic acid, and 10-bromodecanoic acid were all individually supplemented at 20 g each and successfully polymerized with yields ranging from 66.8 to 99.0% (9.24 to 18.2 g L). Using this bioreactor strategy, co-fatty acid feeds of octanoic acid/decanoic acid and octanoic acid/10-azidodecanoic acid (8:2 mol ratio each) resulted in the production of their respective copolymers at nearly the same ratio and at high yield, demonstrating that these methods can be used to control PHA copolymer composition.
PubMed: 33718339
DOI: 10.3389/fbioe.2021.618259 -
Brain Sciences Oct 2017This review focuses on biomarkers associated with the outcome of traumatic brain injury (TBI) patients, such as caspase-3; total antioxidant capacity; melatonin; S100B... (Review)
Review
This review focuses on biomarkers associated with the outcome of traumatic brain injury (TBI) patients, such as caspase-3; total antioxidant capacity; melatonin; S100B protein; glial fibrillary acidic protein (GFAP); glutamate; lactate; brain-derived neurotrophic factor (BDNF); substance P; neuron-specific enolase (NSE); ubiquitin carboxy-terminal hydrolase L-1 (UCH-L1); tau; decanoic acid; and octanoic acid.
PubMed: 29076989
DOI: 10.3390/brainsci7110142 -
Natural Product Research Dec 2023Dibromosterculic acid [8-(1,2-dibromo-2-octylcyclopropyl)-octanoic acid], a new synthetic derivative was prepared by bromination of sterculic acid. This synthetic...
Dibromosterculic acid [8-(1,2-dibromo-2-octylcyclopropyl)-octanoic acid], a new synthetic derivative was prepared by bromination of sterculic acid. This synthetic derivative showed strong fungicidal activity against two pathogenic fungal species namely and with minimum inhibitory concentration (MIC) value of 0.007 mg/ml and good bactericidal activity against and with MIC value of 0.015 mg/ml. Cytotoxic activity on both normal (MCF-10A) and cancerous (MDA-MB-468) cell lines revealed that the survivability percentage of normal cells was unaffected, whereas cancerous cells were decreased greatly by dibromosterculic acid with 50% survivability at 9 µg/ml concentration. Molecular-docking using AutoDock 4.2 with Bax exhibited strong pi-sigma interaction with PHE-93, pi-alkyl and alkyl interaction with TRP-139, ARG-89 and PHE-92 whereas MDM2 revealed strong hydrogen bond interaction with GLN-59 and pi-alkyl interaction with PHE-55. All experimental parameters suggested that this synthetic derivative would be valuable for target-specific drug development with nominal side effects.
PubMed: 38148119
DOI: 10.1080/14786419.2023.2294107 -
Nutrients Mar 2023Our previous studies have found that caprylic acid (C8:0) can improve blood lipids and reduce inflammation levels and may be related to the upregulation of the...
Our previous studies have found that caprylic acid (C8:0) can improve blood lipids and reduce inflammation levels and may be related to the upregulation of the p-JAK2/p-STAT3 pathway by ABCA1. This study aims to investigate the effects of C8:0 and eicosapentaenoic acid (EPA) on lipids, inflammatory levels, and the JAK2/STAT3 pathway in ABCA1-deficient mice (ABCA1) and ABCA1 knock-down (ABCA1-KD) RAW 264.7 cells. Twenty 6-week ABCA1 mice were randomly divided into four groups and fed a high-fat diet, or a diet of 2% C8:0, 2% palmitic acid (C16:0) or 2% EPA for 8 weeks, respectively. The RAW 264.7 cells were divided into the control or control + LPS group, and the ABCA1-KD RAW 264.7 cells were divided into ABCA1-KD with LPS (LPS group), ABCA1-KD with LPS + C8:0 (C8:0 group), and ABCA1-KD with LPS + EPA (EPA group). Serum lipid profiles and inflammatory levels were measured, and ABCA1 and JAK2/STAT3 mRNA and protein expressions were determined by RT-PCR and Western blot analyses, respectively. Our results showed that serum lipid and inflammatory levels increased in ABCA1 mice ( < 0.05). After the intervention of different fatty acids in ABCA1 mice, TG and TNF-α were significantly lower, while MCP-1 increased significantly in the C8:0 group ( < 0.05); however, LDL-C, TC, TNF-α, IL-6, and MCP-1 levels decreased significantly and IL-10 increased significantly in the EPA group ( < 0.05). In the aorta of ABCA1 mice, C8:0 significantly decreased p-STAT3 and p-JAK2 mRNA, while EPA significantly reduced TLR4 and NF-κBp65 mRNA. In the ABCA1-KD RAW 264.7 cells, TNF-α and MCP-1 were increased significantly and IL-10 and IL-1β were significantly decreased in the C8:0 group ( < 0.05). The protein expressions of ABCA1 and p-JAK2 were significantly higher, and the NF-κBp65 was significantly lower in the C8:0 and EPA groups ( < 0.05). Meanwhile, compared to the C8:0 group, the NF-κBp65 protein expression was significantly lower in the EPA group ( < 0.05). Our study showed that EPA had better effects than C8:0 on inhibiting inflammation and improving blood lipids in the absence of ABCA1. C8:0 may be involved mainly in inhibiting inflammation through upregulation of the ABCA1 and p-JAK2/p-STAT3 pathways, while EPA may be involved mainly in inhibiting inflammation through the TLR4/NF-κBp65 signaling pathway. The upregulation of the ABCA1 expression pathway by functional nutrients may provide research targets for the prevention and treatment of atherosclerosis.
Topics: Mice; Animals; Interleukin-10; RAW 264.7 Cells; Eicosapentaenoic Acid; Tumor Necrosis Factor-alpha; Lipopolysaccharides; Caprylates; Toll-Like Receptor 4; Inflammation; RNA, Messenger; ATP Binding Cassette Transporter 1
PubMed: 36904298
DOI: 10.3390/nu15051296 -
Molecules (Basel, Switzerland) Apr 2021The change in phenols, polysaccharides and volatile profiles of noni juice from laboratory- and factory-scale fermentation was analyzed during a 63-day fermentation...
The change in phenols, polysaccharides and volatile profiles of noni juice from laboratory- and factory-scale fermentation was analyzed during a 63-day fermentation process. The phenol and polysaccharide contents and aroma characteristics clearly changed according to fermentation scale and time conditions. The flavonoid content in noni juice gradually increased with fermentation. Seventy-three volatile compounds were identified by solid-phase microextraction coupled with gas chromatography-mass spectrometry (SPME-GC-MS). Methyl hexanoate, 3-methyl-3-buten-1-ol, octanoic acid, hexanoic acid and 2-heptanone were found to be the main aroma components of fresh and fermented noni juice. A decrease in octanoic acid and hexanoic acid contents resulted in the less pungent aroma in noni juice from factory-scale fermentation. The results of principal component analysis of the electronic nose suggested that the difference in nitrogen oxide, alkanes, alcohols, and aromatic and sulfur compounds, contributed to the discrimination of noni juice from different fermentation times and scales.
Topics: Electronic Nose; Fermentation; Gas Chromatography-Mass Spectrometry; Kinetics; Morinda; Phenols; Polysaccharides; Volatile Organic Compounds
PubMed: 33946973
DOI: 10.3390/molecules26092604 -
Angewandte Chemie (International Ed. in... Oct 2022The production of L-lactide from L-lactic acid involves a substantial formation of meso-lactide as an impurity, and, upon polymerization with the industrial catalyst tin...
The production of L-lactide from L-lactic acid involves a substantial formation of meso-lactide as an impurity, and, upon polymerization with the industrial catalyst tin octanoate, results in poly(L-lactic acid) of reduced crystallinity due to stereoerrors randomly distributed along the polymer chains. We describe a new approach wherein, instead of avoiding stereoerrors by removing the meso-lactide prior to polymerization, the stereoerrors in the polymer are tolerated, by crowding them in a stereogradient copolymer. A zirconium complex of an amine tris(phenolate) ligand is found to exhibit very high syndioselectivity in the ring opening polymerization catalysis of meso-lactide at room temperature, and gives rise to stereogradient copolymers in the polymerization of mixtures of meso-lactide/L-lactide in the melt at 180 °C. Relative to the stereo-random copolymers obtained with tin octanoate, the stereogradient copolymers exhibit enhanced crystallinities manifested in lower solubilities and higher melting temperatures and enthalpies.
Topics: Amines; Caprylates; Dioxanes; Lactic Acid; Ligands; Polyesters; Polymers; Tin; Zirconium
PubMed: 35789524
DOI: 10.1002/anie.202207652 -
Bioorganic & Medicinal Chemistry Letters Jun 2023Bacterial resistance has led to increased interest in the use of antibacterial peptides (AMPs), but their clinical application is limited by poor stability and...
Bacterial resistance has led to increased interest in the use of antibacterial peptides (AMPs), but their clinical application is limited by poor stability and solubility, as well as complex cytotoxicity. Chemical modification is a common strategy to modulate AMPs. In this study, a de novo designed AMP (G3) was modified by adding an alkyl acid at the N-terminal and a monosaccharide at the C-terminal. Bio-activity assays demonstrated that conjugation with n-caprylic acid increased the peptide's antibacterial activity and permeabilized the membrane. Attachment of glucose or galactose at the C-terminal improved its biofilm inhibitory capacity and marginally reduced cytotoxicity. The hybrid peptide, containing both n-caprylic acid and galactose, exhibited excellent antibacterial and antibiofilm activity, as well as permeabilized the outer membrane.
Topics: Antimicrobial Cationic Peptides; Glycosylation; Galactose; Anti-Bacterial Agents; Microbial Sensitivity Tests
PubMed: 37182609
DOI: 10.1016/j.bmcl.2023.129322