Gold Nanoparticle-Based Photo-Cross-Linking Strategy for Cellular Target Identification of Supercomplex Molecular Systems.

Cellular target identification plays an essential role in innovative drug development and pharmacological mechanism elucidation. However, very few practical experimental methodologies have been developed for identifying target proteins for supercomplex molecular systems such as biologically active phytochemicals or pharmaceutical compositions. To overcome this limitation, we synthesized gold nanoparticles (AuNPs) as solid scaffolds, which were bound with 4,4'-dihydroxybenzophenone (DHBP) as a photo-cross-linking group on the surface. Then, DHBP-modified AuNPs cross-linked various organic compounds from phytochemicals under ultraviolet radiation via carbene reactions, H-C bond insertion, for catalytic C-C bond formation. We next used the phytochemical-cross-linked AuNPs (phytoAuNPs) to pull down potential binding proteins from brain tissue lysate and identified 13 neuroprotective targets by mass spectrometry analysis. As an exemplary study, we selected Hsp60 as a crucial cellular target to further screen 14 target-binding compounds from phytochemicals through surface plasmon resonance (SPR) analysis, followed by Hsp60 activity detection and neuroprotective effect assay in cells. Collectively, this gold nanoparticle-based photo-cross-linking strategy can serve as a useful platform for discovering novel cellular targets for supercomplex molecular systems and help to explore pharmacological mechanisms and active substances.

[Neuroprotective effects and mechanism of ethanol extract of Cistanche tubulosa against oxygen-glucose deprivation/reperfusion].

To investigate the inhibitory effects and mechanism of Cistanche tubulosa ethanol extract( CTEE) against oxygen-glucose deprivation/reperfusion( OGD/R)-induced PC12 cells neuronal injury. In this study,OGD/R-induced PC12 cells were used to explore the neuroprotective effects of CTEE( 12. 5,25,50 mg·L-1) by detecting cell viability with MTT assay,apoptosis with AO/EB and Hoechst 33258,mitochondrial membrane potential changes with JC-1 staining,mitochondrial oxidative stress with MitoSOX staining,as well as the apoptosis-related protein expression( PARP,cleaved PARP,caspase-3,cleaved caspase-3,Bax,Bcl-2) with Western blot. RESULTS:: showed that CTEE effectively protected OGD/R-induced neuronal injury and increased the survival rate of PC12 cells.AO/EB and Hoechst 33258 staining showed that CTEE could effectively inhibit apoptosis. Moreover,JC-1 and MitoSOX staining results showed that CTEE decreased mitochondrial stress and mitochondrial membrane potential imbalance in PC12 cells in a concentration-dependent manner. Meanwhile,CTEE could obviously suppress the activation of key proteins in mitochondrial apoptosis pathway such as caspase-3 and PARP,and significantly inhibit the rise of Bax and down-regulation of Bcl-2. In conclusion,CTEE has obvious protective effects on OGD/R-induced PC12 cells neuronal injury,potentially via inhibiting mitochondrial oxidative stress and apoptosis-related signaling pathway.

[Study of PbSe quantum dots for use in luminescence solar concentrators].

With the study of the characteristic of luminescence solar concentrator, a simple and practicable Monte Carlo simulation system was invented based on ray tracing method. PbSe quantum dots were successfully introduced into this system, and the optical parameter and quantum dots concentration were simulated and optimized. The cost per unit of the solar cell base on luminescence solar concentrator was investigated, and it was found that the cost of traditional solar cells can be reduced by 49.2%.

Allosteric Regulation of IGF2BP1 as a Novel Strategy for the Activation of Tumor Immune Microenvironment.

Tumor immune microenvironment (TIME) regulators are promising cancer immunotherapeutic targets. IGF2BP1, as a crucial N 6-methyladenosine (m6A) reader protein, recognizes m6A target transcripts, ultimately leading to cancer development. However, currently, the biological function of IGF2BP1 in regulating the TIME is not well-understood. In this study, we report that IGF2BP1 knockdown induces cancer cell apoptosis, thereby significantly not only activating immune cell infiltration including CD4+, CD8+ T cells, CD56+ NK cells, and F4/80+ macrophage but also decreasing PD-L1 expression in hepatocellular carcinoma (HCC). Then, chemical genetics identifies a small-molecule cucurbitacin B (CuB), which directly targets IGF2BP1 at a unique site (Cys253) in the KH1-2 domains. This leads to a pharmacological allosteric effect to block IGF2BP1 recognition of m6A mRNA targets such as c-MYC, which is highly associated with cell apoptosis and immune response. In vivo, CuB exhibits an obvious anti-HCC effect through inducing apoptosis and subsequently recruits immune cells to tumor microenvironment as well as blocking PD-L1 expression. Collectively, IGF2BP1 may serve as a novel pharmacological allosteric target for anticancer therapeutics via mediating TIME.

Neuroinflammation inhibition by small-molecule targeting USP7 noncatalytic domain for neurodegenerative disease therapy.

Neuroinflammation is a fundamental contributor to progressive neuronal damage, which arouses a heightened interest in neurodegenerative disease therapy. Ubiquitin-specific protease 7 (USP7) has a crucial role in regulating protein stability in multiple biological processes; however, the potential role of USP7 in neurodegenerative progression is poorly understood. Here, we discover the natural small molecule eupalinolide B (EB), which targets USP7 to inhibit microglia activation. Cocrystal structure reveals a previously undisclosed covalent allosteric site, Cys576, in a unique noncatalytic HUBL domain. By selectively modifying Cys576, EB allosterically inhibits USP7 to cause a ubiquitination-dependent degradation of Keap1. Keap1 function loss further results in an Nrf2-dependent transcription activation of anti-neuroinflammation genes in microglia. In vivo, pharmacological USP7 inhibition attenuates microglia activation and resultant neuron injury, thereby notably improving behavioral deficits in dementia and Parkinson's disease mouse models. Collectively, our findings provide an attractive future direction for neurodegenerative disease therapy by inhibiting microglia-mediated neuroinflammation by targeting USP7.

Solubility of disodium 5'-guanylate heptahydrate in aqueous methanol mixtures.

The solubility of disodium 5'-guanylate heptahydrate (5'-GMPNa2) in binary aqueous methanol solvent mixtures with the temperature ranging from 278.15 to 323.15K was measured by a dynamic method with a laser monitoring observation technique. The solubility data were correlated with the Combined Nearly Ideal Binary Solvent/Redlich-Kister (CNIBS/R-K) model and the modified Jouyban-Acree model, respectively. For the ten groups of data studied, the CNIBS/R-K model was found to provide a more accurate mathematical representation of the experimental data, while the modified Jouyban-Acree model containing provisions for correlating both the solvent composition and temperature.

Small molecule induces mitochondrial fusion for neuroprotection via targeting CK2 without affecting its conventional kinase activity.

Mitochondrial fusion/fission dynamics plays a fundamental role in neuroprotection; however, there is still a severe lack of therapeutic targets for this biological process. Here, we found that the naturally derived small molecule echinacoside (ECH) significantly promotes mitochondrial fusion progression. ECH selectively binds to the previously uncharacterized casein kinase 2 (CK2) α' subunit (CK2α') as a direct cellular target, and genetic knockdown of CK2α' abolishes ECH-mediated mitochondrial fusion. Mechanistically, ECH allosterically regulates CK2α' conformation to recruit basic transcription factor 3 (BTF3) to form a binary protein complex. Then, the CK2α'/BTF3 complex facilitates ß-catenin nuclear translocation to activate TCF/LEF transcription factors and stimulate transcription of the mitochondrial fusion gene Mfn2. Strikingly, in a mouse middle cerebral artery occlusion (MCAO) model, ECH administration was found to significantly improve cerebral injuries and behavioral deficits by enhancing Mfn2 expression in wild-type but not CK2α'+/- mice. Taken together, our findings reveal, for the first time, that CK2 is essential for promoting mitochondrial fusion in a Wnt/ß-catenin-dependent manner and suggest that pharmacologically targeting CK2 is a promising therapeutic strategy for ischemic stroke.

Anti-tumor and Phenotypic Regulation Effect of Matrine on Dendritic Cells through Regulating TLRs Pathway.

OBJECTIVE: To investigate the effects of matrine on antigen presentation of dendritic cells (DCs), and to explore the pharmacological mechanism of matrine on anti-tumor effect. METHODS: Different concentrations (0, 1, 2, 4, 8 and 16 µ g/mL) of matrine were co-cultured with DCs, the harvested DCs were co-cultured with antigens of Lewis lung cancer (LLC) cells, and then DCs and T cells were co-cultured to produce DCs-activated killer (DAK) cells, which have significant tumor-killing activity. The expression of cytokines, mRNA and protein of toll-like receptors (TLRs) in DCs were detected by enzyme linked immunosobent assay, polymerase chain reaction and Western blot, respectively. And the killing effect of DAK were measured by MTT assay. RESULTS: Matrine significantly increased the mRNA expression of TLR7, TLR8, myeloid differentiation factor 88 (MyD88), tumor necrosis factor receptor-associated factor 6 (TRAF-6) and I κ B kinase (IKK), as well as the protein expression of TLR7 and TLR8, and up-regulated the levels of interleukin-12 (IL-12), IL-6 and tumor necrosis factor-α (TNF-α), meanwhile, it also increased the expressions of MHC-II, CD54, CD80 and CD86 in DCs. DCs-activated effector T cells had significant tumor-killing activity. When the concentration of matrine was more than 4 µg/mL, all indices had significant difference (P<0.01 or P<0.05). CONCLUSION: Matrine plays an anti-tumor role by regulating TLRs signal transduction pathway, promoting the secretion of inflammatory cytokines and enhancing immune function.

Protosappanin A Maintains Neuronal Mitochondrial Homeostasis through Promoting Autophagic Degradation of Bax.

Cerebral ischemia is accompanied by mitochondrial integrity destruction. Thus, reversion of mitochondrial damage holds great potential for cerebral ischemia therapy. As a crucial Bcl-2 family member, pro-apoptotic Bax protein is a main effector of mitochondrial permeabilization and plays an important role in mitochondrial homeostasis. However, there is still a lack of an effective cerebral protective strategy through selectively targeting Bax. In this study, we reported that natural small-molecule protosappanin A (PTA) showed a significant mitochondrial protective effect on oxygen-glucose deprivation/reperfusion (OGD/R)-induced PC12 cells injury through increasing ATP production and maintaining mitochondrial DNA (mtDNA) content. The mechanism study revealed that PTA selectively induced pro-apoptotic protein Bax degradation, without affecting other Bcl-2 family members such as Bcl-2, Bcl-xl, Bad, Puma, Bid, Bim, and Bik. In addition, we found that PTA promoted the association of autophagosomal marker LC3B to Bax for its degradation via an autophagy-dependent manner but not the ubiquitin-proteasome pathway. Collectively, our findings offered a new pharmacological strategy for maintaining mitochondrial function by inducing autophagic degradation of Bax and also provided a novel drug candidate against ischemic neuronal injury.

Aglaia odorata Lour. extract inhibit ischemic neuronal injury potentially via suppressing p53/Puma-mediated mitochondrial apoptosis pathway.

ETHNOPHARMACOLOGICAL RELEVANCE: Aglaia odorata Lour. is a traditional Chinese medicinal plant possessing properties of improving blood circulation, and it is widely used in the treatment of dizziness, traumatic injuries and bruises. AIM OF STUDY: In this study, we are aimed to investigate the cerebral protection effect of the extracts from leaves of Aglaia odorata Lour. (ELA) and the potential mechanism in vivo and in vitro. MATERIALS AND METHODS: The therapeutic effect of ELA on ischemic cerebral stroke was measured on a middle cerebral artery occlusion (MCAO) rat model. Protective effect of ELA on oxygen-glucose deprivation/reperfusion (OGD/R)-induced PC12 cells was measured by MTT assay. The apoptotic cells were observed by Hoechst 33258 staining and acridine orange/ethidium bromide double staining assay. Mitochondria were observed by Mitotracker staining assay. The mitochondrial membrane potential was determined by JC-1 staining assay. Western blot was used to investigate the effects of ELA on apoptosis-related proteins. RESULTS: We showed that ELA was an effective neuroprotective agent. In vivo experiments, ELA exerted significant protective effect on MCAO model. TTC staining showed that ELA could reduce cerebral infarction area against MCAO insult. HE and Nissl's staining indicated that ELA could reverse the damage of cortex and hippocampus caused by MCAO. In vitro experiments, ELA showed significant protective effect on OGD/R-induced PC12 cells by reducing the number of apoptotic cells, increasing mitochondrial membrane potential, and reducing superoxide aggregation, further suppressing mitochondrial caspase-9/3 apoptosis pathway. Moreover, protective effect of ELA on mitochondrial function may be exerted by inhibiting p53/Puma signal pathway. CONCLUSION: Our results suggest that ELA exerts a marked neuroprotective effect against cerebral ischemia potentially via suppressing p53/Puma-mediated mitochondrial caspase-9/3 apoptosis pathway.

Mechanism, synthesis and modification of nano zerovalent iron in water treatment.

Owing to its strong reducing ability, high reaction activity, excellent adsorption properties, good mobility and relatively low cost, nano zerovalent iron (nZVI) is an extremely promising nanomaterial for use in water treatment. In this paper, the working mechanisms of nZVI in the degradation of various contaminants in water are outlined and discussed. Synthesis methods and their respective advantages and disadvantages are discussed in detail. Furthermore, a variety of modification methods which have been developed to improve the mobility and stability of nZVI as well as to facilitate the separation of nZVI from degraded systems are also summarized and discussed. Numerous studies indicate that nZVI has considerable potential to become an efficient, versatile and practical approach for large-scale water treatment.

Structural characterization and enantioseparation of the chiral compound praziquantel.

In this study, we aimed to characterize the chiral compound type of a leading antischistosomal drug, praziquantel. The optically pure praziquantel enantiomers were recovered from the racemic mixture by enantiomeric separation, which was performed on preparative scale chromatography by using a novel beta-cyclodextrin type chiral column. The thermodynamic properties of praziquantel were determined from differential scanning calorimetry and the physical properties were studied by examining Fourier transform infrared spectroscopy and X-ray powder diffraction. Based on the differential scanning calorimetry data, a melting point binary phase diagram was constructed. A ternary solubility phase diagram of praziquantel in methanol was also determined at the temperature of 0 degrees C. All the experimental results support the conclusion that praziquantel is a racemic compound. The characterization of physical properties of praziquantel and the phase diagram are crucial for understanding the rationality for the successful resolution of praziquantel and also provide the basis for designing the strategy of separation and recovery of pure enantiomer.

Investigation of the phase diagrams of chiral praziquantel.

In the present work, thermal properties of praziquantel, including melting point phase diagram and solubility, were determined for the purpose of exploration on an integrated enantioseparation process of chromatography and crystallization. The solubility of racemic praziquantel in methanol and 2-propanol was measured in the temperature range between 0 and 40 degrees C. In agreement with previous conclusions, the resulting phase diagram reveals the racemic compound behavior of praziquantel arising from the existence of eutectics. A ternary phase diagram of praziquantel enantiomers and the methanol system was also determined. Based on the information provided by the ternary solubility phase diagram, an optimized integrated enantioseparation process was suggested. Pure praziquantel crystals were recovered, and the crystal structure was solved by X-ray crystallography.