Preferred Endocytosis of Amyloid Precursor Protein from Cholesterol-Enriched Lipid Raft Microdomains

Amyloid precursor protein (APP) at the plasma membrane is internalized via endocytosis and delivered to endo/lysosomes, where neurotoxic amyloid-β (Aβ) is produced via β-, γ-secretases. Hence, endocytosis plays a key role in the processing of APP and subsequent Aβ generation. β-, γ-secretases as well as APP are localized in cholesterol-enriched lipid raft microdomains. However, it is still unclear whether lipid rafts are the site where APP undergoes endocytosis and whether cholesterol levels affect this process. In this study, we found that localization of APP in lipid rafts was increased by elevated cholesterol level. We also showed that increasing or decreasing cholesterol levels increased or decreased APP endocytosis, respectively. When we labeled cell surface APP, APP localized in lipid rafts preferentially underwent endocytosis compared to nonraft-localized APP. In addition, APP endocytosis from lipid rafts was regulated by cholesterol levels. Our results demonstrate for the first time that cholesterol levels regulate the localization of APP in lipid rafts affecting raft-dependent APP endocytosis. Thus, regulating the microdomain localization of APP could offer a new therapeutic strategy for Alzheimer’s disease.     

Chain ordering of Stratum corneum lipids investigated by EPR slow-tumbling simulation

We investigated the chain ordering of the lipid bilayer of Stratum corneum (SC) using an electron paramagnetic resonance (EPR) spin probe method in conjunction with slow-tumbling simulation. The ordering of SC lipids was evaluated by analysis of the signals of 5-doxylstearic acid (5-DSA) spin probe incorporated into the lamellar lipids. The result obtained with the conventional method of calculating the order parameter using hyperfine values was 0.80. The value of the order parameter obtained by spectral simulation was 0.73. It was found that the conventional method of calculating the chain ordering using hyperfine values could not differentiate subtle EPR spectral changes. However, EPR slow-tumbling simulation can differentiate such subtle spectral changes. Thus, the present EPR investigation suggests that simulation provides more detail about the structure of the lipid bilayer than the conventional method.     

Interaction of tetraphenyl-porphyrin derivatives with DPPC-liposomes: an EPR study

The effect of the symmetry and polarity of the porphyrin molecules on their membrane localization and interaction with membrane lipids were investigated by electron paramagnetic resonance (EPR). For this purpose, two glycoconjugated tetraphenyl porphyrin derivatives were selected, respectively, symmetrically and asymmetrically substituted. Small unilamellar liposomes composed of dipalmitoylphosphatidylcholine (DPPC) and spin labeled stearic acids were prepared. The spin probe was located at the 5th or 7th or 12th or 16th position of the hydrocarbon chain in order to monitor various regions of the lipid bilayer. EPR spectra of porphyrin-free and porphyrin-bound liposomes were recorded at various temperatures below and above the phase transition temperature of DPPC. The effect on membrane fluidity proved to be stronger with the asymmetrical porphyrin derivative than with the symmetrical one. The rigidity increased when the spin label was near lipid head groups. The difference observed between control and porphyrin-treated samples when measured below the main lipid transition temperature disappeared at higher temperature. When the spin label was near the end of the hydrophobic tails, the symmetrical porphyrin derivative caused increase in fluidity, while the asymmetrical one slightly decreased it. To explain this phenomenon we propose that the asymmetrical derivative exerts a stronger ordering effect caused by its fluorophenyl group located at the level of the lipid heads, which is attenuated to the hydrophobic tails. The perturbing effect of the symmetric derivative could not lead to similar extent of ordering at the head groups and looses the hydrocarbon chains deeper in the membrane.     

Preparation and Properties of Cyclodextrin Inclusion Complexes of Hyperoside

In order to improve the aqueous solubility and enhance the bioavailability of Hyperoside (Hyp), three inclusion complexes (ICs) of Hyp with 2-hydroxypropyl-β-cyclodextrin (2H-β-CD), β-cyclodextrin (β-CD), and methyl-β-cyclodextrin (M-β-CD) were prepared using the ultrasonic method. The characterization of the inclusion complexes (ICs) was achieved using Fourier-transform infrared spectroscopy (FTIR), scanning electronic microscopy (SEM), X-ray powder diffraction (XRPD), thin-layer chromatography (TLC), and ¹H nuclear magnetic resonance (¹H NMR). The effects of the ICs on the solubility and antioxidant activity of Hyp were investigated. A Job’s plot revealed that the Hyp formed ICs with three kinds of cyclodextrin (CD), all at a 1:1 stoichiometric ratio. The FTIR, SEM, XRPD, TLC, and ¹H NMR results confirmed the formation of inclusion complexes. The water solubility of the IC of Hyp with 2-hydroxypropyl-β-cyclodextrin was enhanced 9-fold compared to the solubility of the original Hyp. The antioxidant activity tests showed that the inclusion complexes had higher antioxidant activities compared to free Hyp in vitro and the H₂O₂–RAW264.7 cell model. Therefore, encapsulation with CDs can not only improve Hyp’s water solubility but can also enhance its biological activity, which provides useful information for the potential application of complexation with Hyp in a clinical context.     

EPR spin probe investigation of irradiated wheat,rice and sunflower seeds

TEMPO and 4-nitro-TEMPO spin probes were used to monitor dose-dependent changes in the EPR spectra of irradiated wheat and rice embryos and sunflower embryo parts. Rice embryos were studied in the 233–293 K temperature range using 4-nitro-TEMPO. TEMPAMINE, TEMPYO and DTBN spin probes were also studied for their applicability in the determination of irradiated seeds. All the recorded spectra were simulated, and spectral parameters and partition of the probes among various domains were determined. Despite the contribution of the signal from extracellular regions, it was possible to detect the changes in the water/lipid ratios with dose. The hydrophilic character of the probe alone was not sufficient to distinguish the different doses of irradiation. Line widths and rotational correlation times of various domains within embryo also play an important role. Partition after dehydration was another measure in the selection of the suitable probes for irradiation studies. Better results were obtained in dehydrated embryos for the probes preferring lipid bodies.     

Crystal Structure and Solid-State Packing of 4-Chloro-5H-1,2,3-dithiazol-5-one and 4-Chloro-5H-1,2,3-dithiazole-5-thione

The crystal structure and solid-state packing of 4-chloro-5H-1,2,3-dithiazol-5-one and two polymorphs of 4-chloro-5H-1,2,3-dithiazole-5-thione were analyzed and compared to structural data of similar systems. These five-membered S,N-rich heterocycles are planar with considerable bond localization. All three structures demonstrate tight solid-state packing without voids which is attributed to a rich network of short intermolecular electrostatic contacts. These include S^δ+…N^δ−, S^δ+…O^δ−, S^δ+…Cl^δ− and S^δ+…S^δ− interactions that are well within the sum of their van der Waals radii (∑_VDW). B3LYP, BLYP, M06, mPW1PW, PBE and MP2 were employed to calculate their intramolecular geometrical parameters, the Fukui condensed functions to probe their reactivity, the bond order, Bird Index and NICS(1) to establish their aromaticity.     

Effects of Pueraria candollei var mirifica (Airy Shaw and Suvat.) Niyomdham on Ovariectomy-Induced Cognitive Impairment and Oxidative Stress in the Mouse Brain

The effects of the phytoestrogen-enriched plant Pueraria mirifica (PM) extract on ovari-ectomy (OVX)-induced cognitive impairment and hippocampal oxidative stress in mice were investigated. Daily treatment with PM and 17β-estradiol (E2) significantly elevated cognitive behavior as evaluated by using the Y maze test, the novel object recognition test (NORT), and the Morris water maze test (MWM), attenuated atrophic changes in the uterus and decreased serum 17β-estradiol levels. The treatments significantly ameliorated ovariectomy-induced oxidative stress in the hippocampus and serum by a decrease in malondialdehyde (MDA), an enhancement of superoxide dismutase, and catalase activity, including significantly down-regulated expression of IL-1β, IL-6 and TNF-α proinflammatory cytokines, while up-regulating expression of PI3K. The present results suggest that PM extract suppresses oxidative brain damage and dysfunctions in the hippocampal antioxidant system, including the neuroinflammatory system in OVX animals, thereby preventing OVX-induced cognitive impairment. The present results indicate that PM exerts beneficial effects on cognitive deficits for which menopause/ovariectomy have been implicated as risk factors.     

N,N-Diethyl-3-toluamide Formulation Based on Ethanol Containing 0.1% 2-Hydroxypropyl-β-cyclodextrin Attenuates the Drug’s Skin Penetration and Prolongs the Repellent Effect without Stickiness

N,N-diethyl-3-toluamide (DEET) is one of the most widely used insect repellents in the world. It was reported that a solution containing 6–30% cyclodextrin (CD) as a solvent instead of ethanol (EtOH) provided an enhancement of the repellent action time duration of the DEET formulation, although the high-dose CD caused stickiness. In order to overcome this shortcoming, we attempted to prepare a 10% DEET formulation using EtOH containing low-dose CDs (β-CD, 2-hydroxypropyl-β-CD (HPβCD), methyl-β-CD, and sulfobutylether-β-CD) as solvents (DEET/EtOH/CD formulations). We determined the CD concentration to be 0.1% in the DEET/EtOH/CD formulations, since the stickiness of 0.1% CDs was not felt (approximately 8 × 10⁻³ N). The DEET residue on the skin superficial layers was prolonged, and the drug penetration into the skin tissue was decreased by the addition of 0.1% CD. In particular, the retention time and attenuated penetration of DEET on the rat skin treated with the DEET/EtOH/HPβCD formulation was significantly higher in comparison with that of the DEET/EtOH formulation without CD. Moreover, the repellent effect of DEET was more sustained by the addition of 0.1% HPβCD in the study using Aedes albopictus. In conclusion, we found that the DEET/EtOH/HPβCD formulations reduced the skin penetration of DEET and prolonged the repellent action without stickiness.     

Uptake of Cell-Penetrating Peptide RL2 by Human Lung Cancer Cells: Monitoring by Electron Paramagnetic Resonance and Confocal Laser Scanning Microscopy

RL2 is a recombinant analogue of a human κ-casein fragment, capable of penetrating cells and inducing apoptosis of cancer cells with no toxicity to normal cells. The exact mechanism of RL2 penetration into cells remains unknown. In this study, we investigated the mechanism of RL2 penetration into human lung cancer A549 cells by a combination of electron paramagnetic resonance (EPR) spectroscopy and confocal laser scanning microscopy. EPR spectra of A549 cells incubated with RL2 (sRL2) spin-labeled by a highly stable 3-carboxy-2,2,5,5-tetraethylpyrrolidine-1-oxyl radical were found to contain three components, with their contributions changing with time. The combined EPR and confocal-microscopy data allowed us to assign these three forms of sRL2 to the spin-labeled protein sticking to the membrane of the cell and endosomes, to the spin-labeled protein in the cell interior, and to spin labeled short peptides formed in the cell because of protein digestion. EPR spectroscopy enabled us to follow the kinetics of transformations between different forms of the spin-labeled protein at a minimal spin concentration (3–16 μM) in the cell. The prospects of applications of spin-labeled cell-penetrating peptides to EPR imaging, DNP, and magnetic resonance imaging are discussed, as is possible research on an intrinsically disordered protein in the cell by pulsed dipolar EPR spectroscopy.     

β-Sitosterol-D-Glucopyranoside Mimics Estrogenic Properties and Stimulates Glucose Utilization in Skeletal Muscle Cells

Estrogenic molecules have been reported to regulate glucose homeostasis and may be beneficial for diabetes management. Here, we investigated the estrogenic effect of β-sitosterol-3-O-D-glucopyranoside (BSD), isolated from the fruits of Cupressus sempervirens and monitored its ability to regulate glucose utilization in skeletal muscle cells. BSD stimulated ERE-mediated luciferase activity in both ERα and ERβ-ERE luc expression system with greater response through ERβ in HEK-293T cells, and induced the expression of estrogen-regulated genes in estrogen responsive MCF-7 cells. In silico docking and molecular interaction studies revealed the affinity and interaction of BSD with ERβ through hydrophobic interaction and hydrogen bond pairing. Furthermore, prolonged exposure of L6-GLUT4myc myotubes to BSD raised the glucose uptake under basal conditions without affecting the insulin-stimulated glucose uptake, the effect associated with enhanced translocation of GLUT4 to the cell periphery. The BSD-mediated biological response to increase GLUT4 translocation was obliterated by PI-3-K inhibitor wortmannin, and BSD significantly increased the phosphorylation of AKT (Ser-473). Moreover, BSD-induced GLUT4 translocation was prevented in the presence of fulvestrant. Our findings reveal the estrogenic activity of BSD to stimulate glucose utilization in skeletal muscle cells via PI-3K/AKT-dependent mechanism.     

Study of Integer Spin S = 1 in the Polar Magnet β-Ni(IO3)2

Polar magnetic materials exhibiting appreciable asymmetric exchange interactions can potentially host new topological states of matter such as vortex-like spin textures; however, realizations have been mostly limited to half-integer spins due to rare numbers of integer spin systems with broken spatial inversion lattice symmetries. Here, we studied the structure and magnetic properties of the S = 1 integer spin polar magnet β-Ni(IO₃)₂ (Ni²⁺, d⁸, ³F). We synthesized single crystals and bulk polycrystalline samples of β-Ni(IO₃)₂ by combining low-temperature chemistry techniques and thermal analysis and characterized its crystal structure and physical properties. Single crystal X-ray and powder X-ray diffraction measurements demonstrated that β-Ni(IO₃)₂ crystallizes in the noncentrosymmetric polar monoclinic structure with space group P2₁. The combination of the macroscopic electric polarization driven by the coalignment of the (IO₃)⁻ trigonal pyramids along the b axis and the S = 1 state of the Ni²⁺ cation was chosen to investigate integer spin and lattice dynamics in magnetism. The effective magnetic moment of Ni²⁺ was extracted from magnetization measurements to be 3.2(1) µ_B, confirming the S = 1 integer spin state of Ni²⁺ with some orbital contribution. β-Ni(IO₃)₂ undergoes a magnetic ordering at T = 3 K at a low magnetic field, μ₀H = 0.1 T; the phase transition, nevertheless, is suppressed at a higher field, μ₀H = 3 T. An anomaly resembling a phase transition is observed at T ≈ 2.7 K in the C_p/T vs. T plot, which is the approximate temperature of the magnetic phase transition of the material, indicating that the transition is magnetically driven. This work offers a useful route for exploring integer spin noncentrosymmetric materials, broadening the phase space of polar magnet candidates, which can harbor new topological spin physics.     

Synthesis and Characterization of Andrographolide Derivatives as Regulators of βAPP Processing in Human Cells

Alzheimer’s disease (AD) is a devastating neurodegenerative disorder, one of the main characteristics of which is the abnormal accumulation of amyloid peptide (Aβ) in the brain. Whereas β-secretase supports Aβ formation along the amyloidogenic processing of the β-amyloid precursor protein (βAPP), α-secretase counterbalances this pathway by both preventing Aβ production and triggering the release of the neuroprotective sAPPα metabolite. Therefore, stimulating α-secretase and/or inhibiting β-secretase can be considered a promising anti-AD therapeutic track. In this context, we tested andrographolide, a labdane diterpene derived from the plant Andrographis paniculata, as well as 24 synthesized derivatives, for their ability to induce sAPPα production in cultured SH-SY5Y human neuroblastoma cells. Following several rounds of screening, we identified three hits that were subjected to full characterization. Interestingly, andrographolide (8,17-olefinic) and its close derivative 14α-(5′,7′-dichloro-8′-quinolyloxy)-3,19-acetonylidene (compound 9) behave as moderate α-secretase activators, while 14α-(2′-methyl-5′,7′-dichloro-8′-quinolyloxy)-8,9-olefinic compounds 31 (3,19-acetonylidene) and 37 (3,19-diol), whose two structures are quite similar although distant from that of andrographolide and 9, stand as β-secretase inhibitors. Importantly, these results were confirmed in human HEK293 cells and these compounds do not trigger toxicity in either cell line. Altogether, these findings may represent an encouraging starting point for the future development of andrographolide-based compounds aimed at both activating α-secretase and inhibiting β-secretase that could prove useful in our quest for the therapeutic treatment of AD.     

Magnetic and EPR Studies of α-, β-, and γ-Fe2WO6 Phases at Low Temperatures

The polymorphic modifications α-, β-, and γ-Fe₂WO₆ of the iron tungstate system were studied by means of magnetic susceptibility and EPR measurements at low temperatures. Both methods revealed a significant paramagnetic contribution, probably resulting from local distortions of the antiferromagnetic bulk structure induced by a disturbed cation ordering or the presence of Fe²⁺ ions. The magnetic susceptibility revealed a peak at 260 K for all samples which can be related with an AF phase transition. The EPR spectra comprised the contribution of various isolated paramagnetic iron centers, one arising from high-spin Fe³⁺ ions in rhombic crystal field symmetry with E/D ≈ 1/3 and D ≈ 0.22 cm^-1, an anisotropic EPR signal consistent with an S= 3/2 ground state with large zero-field splitting, and a dominant component in the g ≈ 2 region presumably arising from an S = 1/2; spin state. The latter spectra were tentatively attributed to the formation of multi-iron clusters, one of them invoking the presence of Fe²⁺ ions as well. For the βFe₂WO₆ phase an additional EPR spectrum was observed, which probably results from high-spin Fe³⁺ ions in a weak crystal field.     

An Inside Job: Molecular Determinants for Postsynaptic Localization of Nicotinic Acetylcholine Receptors

Nicotinic acetylcholine receptors (nAChRs) mediate fast synaptic transmission at neuromuscular and autonomic ganglionic synapses in the peripheral nervous system. The postsynaptic localization of muscle ((α1)₂β1γδ) and neuronal ((α3β4)₂β4) nicotinic receptors at these synapses is mediated by interactions between the nAChR intracellular domains and cytoplasmic scaffolding proteins. Recent high resolution structures and functional studies provide new insights into the molecular determinants that mediate these interactions. Surprisingly, they reveal that the muscle nAChR binds 1–3 rapsyn scaffolding molecules, which dimerize and thereby form an interconnected lattice between receptors. Moreover, rapsyn binds two distinct sites on the nAChR subunit cytoplasmic loops; the MA-helix on one or more subunits and a motif specific to the β subunit. Binding at the latter site is regulated by agrin-induced phosphorylation of βY390, and increases the stoichiometry of rapsyn/AChR complexes. Similarly, the neuronal nAChR may be localized at ganglionic synapses by phosphorylation-dependent interactions with 14-3-3 adaptor proteins which bind specific motifs in each of the α3 subunit cytoplasmic loops. Thus, postsynaptic localization of nAChRs is mediated by regulated interactions with multiple scaffolding molecules, and the stoichiometry of these complexes likely helps regulate the number, density, and stability of receptors at the synapse.     

Harnessing α-l-fucosidase for in vivo cellular senescence imaging

Precise detection of cellular senescence may allow its role in biological systems to be evaluated more effectively, while supporting studies of therapeutic candidates designed to evade its detrimental effect on physical function. We report here studies of α-l-fucosidase (α-fuc) as a biomarker for cellular senescence and the development of an α-fuc-responsive aggregation induced emission (AIE) probe, termed QM-NHαfuc designed to complement more conventional probes based on β-galactosidase (β-gal). Using QM-NHαfuc, the onset of replicative-, reactive oxygen species (ROS)-, ultraviolet A (UVA)-, and drug-induced senescence could be probed effectively. QM-NHαfuc also proved capable of identifying senescent cells lacking β-gal expression. The non-invasive real-time senescence tracking provided by QM-NHαfuc was validated in an in vivo senescence model. The results presented in this study lead us to suggest that the QM-NHαfuc could emerge as a useful tool for investigating senescence processes in biological systems.

Evidence of close association of α-fuc with senescence induction highlights the potential of α-fuc as a novel biomarker for cellular senescence. Here, an α-fuc-responsive AIE probe (QM-NHαfuc) allows for the identification of senescent cell in vivo.     

Bioactive Tryptophan-Based Copper Complex with Auxiliary β-Carboline Spectacle Potential on Human Breast Cancer Cells: In Vitro and In Vivo Studies

Biocompatible tryptophan-derived copper (1) and zinc (2) complexes with norharmane (β-carboline) were designed, synthesized, characterized, and evaluated for the potential anticancer activity in vitro and in vivo. The in vitro cytotoxicity of both complexes 1 and 2 were assessed against two cancerous cells: (human breast cancer) MCF7 and (liver hepatocellular cancer) HepG2 cells with a non-tumorigenic: (human embryonic kidney) HEK293 cells. The results exhibited a potentially decent selectivity of 1 against MCF7 cells with an IC₅₀ value of 7.8 ± 0.4 μM compared to 2 (less active, IC₅₀ ~ 20 μM). Furthermore, we analyzed the level of glutathione, lipid peroxidation, and visualized ROS generation to get an insight into the mechanistic pathway and witnessed oxidative stress. These in vitro results were ascertained by in vivo experiments, which also supported the free radical-mediated oxidative stress. The comet assay confirmed the oxidative stress that leads to DNA damage. The histopathology of the liver also ascertained the low toxicity of 1.     

Discrepancy between the spin distribution and the magnetic ground state for a triaminoxyl substituted triphenylphosphine oxide derivative

The magnetic interaction and spin transfer via phosphorus have been investigated for the tri-tert-butylaminoxyl para-substituted triphenylphosphine oxide. For this radical unit, the conjugation existing between the pi* orbital of the NO group and the phenyl pi orbitals leads to an efficient delocalization of the spin from the radical to the neighboring aromatic ring. This has been confirmed by using fluid solution high-resolution EPR and solid state MAS NMR spectroscopy. The spin densities located on the atoms of the molecule could be probed since (1)H, (13)C, (14)N, and (31)P are nuclei active in NMR and EPR, and lead to a precise spin distribution map for the triradical. The experimental investigations were completed by a DFT computational study. These techniques established in particular that spin density is located at the phosphorus (rho=-15x10(-3) au), that its sign is in line with the sign alternation principle and that its magnitude is in the order of that found on the aromatic C atoms of the molecule. Surprisingly, whereas the spin distribution scheme supports ferromagnetic interactions among the radical units, the magnetic behavior found for this molecule revealed a low-spin ground state characterized by an intramolecular exchange parameter of J=-7.55 cm(-1) as revealed by solid state susceptibility studies and low temperature EPR. The X-ray crystal structures solved at 293 and 30 K show the occurrence of a crystallographic transition resulting in an ordering of the molecular units at low temperature.     

Phenolic Compounds from Mori Cortex Ameliorate Sodium Oleate-Induced Epithelial–Mesenchymal Transition and Fibrosis in NRK-52e Cells through CD36

Lipid deposition in the kidney can cause serious damage to the kidney, and there is an obvious epithelial–mesenchymal transition (EMT) and fibrosis in the late stage. To investigate the interventional effects and mechanisms of phenolic compounds from Mori Cortex on the EMT and fibrosis induced by sodium oleate-induced lipid deposition in renal tubular epithelial cells (NRK-52e cells), and the role played by CD36 in the adjustment process, NRK-52e cells induced by 200 μmol/L sodium oleate were given 10 μmoL/L moracin-P-2″-O-β-d-glucopyranoside (Y-1), moracin-P-3′-O-β-d-glucopyranoside (Y-2), moracin-P-3′-O-α-l-arabinopyranoside (Y-3), and moracin-P-3′-O-[β-glucopyranoside-(1→2)arabinopyranoside] (Y-4), and Oil Red O staining was used to detect lipid deposition. A Western blot was used to detect lipid deposition-related protein CD36, inflammation-related protein (p-NF-κB-P65, NF-κB-P65, IL-1β), oxidative stress-related protein (NOX1, Nrf2, Keap1), EMT-related proteins (CD31, α-SMA), and fibrosis-related proteins (TGF-β, ZEB1, Snail1). A qRT-PCR test detected inflammation, EMT, and fibrosis-related gene mRNA levels. The TNF-α levels were detected by ELISA, and the colorimetric method was used to detects SOD and MDA levels. The ROS was measured by flow cytometry. A high-content imaging analysis system was applied to observe EMT and fibrosis-related proteins. At the same time, the experiment silenced CD36 and compared the difference between before and after drug treatment, then used molecular docking technology to predict the potential binding site of the active compounds with CD36. The research results show that sodium oleate can induce lipid deposition, inflammation, oxidative stress, and fibrosis in NRK-52e cells. Y-1 and Y-2 could significantly ameliorate the damage caused by sodium oleate, and Y-2 had a better ameliorating effect, while there was no significant change in Y-3 or Y-4. The amelioration effect of Y-1 and Y-2 disappeared after silencing CD36. Molecular docking technology showed that the Y-1 and Y-2 had hydrogen bonds to CD36 and that, compared with Y-1, Y-2 requires less binding energy. In summary, moracin-P-2″-O-β-d-glucopyranoside and moracin-P-3′-O-β-d-glucopyranoside from Mori Cortex ameliorated lipid deposition, EMT, and fibrosis induced by sodium oleate in NRK-52e cells through CD36.     

The Synthesis of a Bis(thiosemicarbazone) Macrocyclic Ligand and the Mn(II), Co(II), Zn(II) and 68Ga(III) Complexes

A 1,4,7,10-tetraazacyclododecane (cyclen) variant bearing two thiosemicarbazone pendant groups has been prepared. The ligand forms complexes with Mn²⁺, Co²⁺ and Zn²⁺. X-ray crystallography of the Mn²⁺, Co²⁺ and Zn²⁺ complexes showed that the ligand provides a six-coordinate environment for the metal ions. The Mn²⁺ and Zn²⁺ complexes exist in the solid state as racemic mixtures of the Δ(δ,δ,δ,δ)/Λ(λ,λ,λ,λ) and Δ(λ,λ,λ,λ)/Λ(δ,δ,δ,δ) diastereomers, and the Co²⁺ complex exists as the Δ(δ,δ,δ,δ)/Λ(λ,λ,λ,λ) and Δ(λ,λ,λ,δ)/Λ(δ,δ,δ,λ) diastereomers. Density functional theory calculations indicated that the relative energies of the diastereomers are within 10 kJ mol⁻¹. Magnetic susceptibility of the complexes indicated that both the Mn²⁺ and Co²⁺ ions are high spin. The ligand was radiolabelled with gallium-68, in the interest of developing new positron emission tomography imaging agents, which produced a single species in high radiochemical purity (>95%) at 90 °C for 10 min.     

Euphorbiasteroid Abrogates EGFR and Wnt/β-Catenin Signaling in Non-Small-Cell Lung Cancer Cells to Impart Anticancer Activity

EGFR and Wnt/β-catenin signaling pathways play a prominent role in tumor progression in various human cancers including non-small-cell lung carcinoma (NSCLC). Transactivation and crosstalk between the EGFR and Wnt/β-catenin pathways may contribute to the aggressiveness of cancers. Targeting these oncogenic pathways with small molecules is an attractive approach to counteract various types of cancers. In this study, we demonstrate the effect of euphorbiasteroid (EPBS) on the EGFR and Wnt/β-catenin pathways in NSCLC cells. EPBS induced preferential cytotoxicity toward A549 (wildtype EGFR-expressing) cells over PC-9 (mutant EGFR-expressing) cells. EPBS suppressed the expression of EGFR, Wnt3a, β-catenin, and FZD-1, and the reduction in β-catenin levels was found to be mediated through the activation of GSK-3β. EPBS reduced the phosphorylation of GSK-3β^S9 with a parallel increase in β-TrCP and phosphorylation of GSK-3β^Y216. Lithium chloride treatment increased the phosphorylation of GSK-3β^S9 and nuclear localization of β-catenin, whereas EPBS reverted these effects. Forced expression or depletion of EGFR in NSCLC cells increased or decreased the levels of Wnt3a, β-catenin, and FZD-1, respectively. Overall, EPBS abrogates EGFR and Wnt/β-catenin pathways to impart its anticancer activity in NSCLC cells.