Synthesis and bioevaluation of Scutellarein-Tertramethylpyrazine hybrid molecules for the treatment of ischemic stroke.

Ischemic stroke caused by insufficient blood supply to the brain may produce a sequence of cascade reactions, leading to oxidative stress and ultimately inducing nerve cell damage. Therefore, hybrid molecules with multiple therapeutic effects have irreplaceable advantages for the treatment of ischemic stroke. Based on the previous works, two types of Scutellarein and Tertramethylpyrazine hybrid molecules were designed and synthesized according to the PepT 1-based design. After systematic research, all synthesized hybrid molecules exhibited more excellent neuroprotective effect and antiplatelet activity compared to the original drugs. Among them, the selected compound 1e with superior neuroprotective and antiplatelet effects could significantly enhance the permeability on the Caco-2 monolayer membrane and inhibit the Gly-Sar uptake on Caco-2 cells. Meanwhile, the result of intestinal perfusion has also confirmed that the absorption of the selected compound 1e is indeed increased. Further, the selected compound 1e significantly reduce the cerebral infarction volume of middle cerebral artery occlusion/reperfusion rats. Especially, the cerebral infarction volume of the high-dose 1e group reduced to one fourth of the model group. Meanwhile, results of hematoxylin-eosin staining also indicated that the damage in the hippocampus CA1 region was significantly alleviated after treatment with the compound 1e. Accordingly, molecular hybridization strategy is one of the simple and feasible ways to improve the therapeutic effect of single targeted drug.

In vivo anti-hyperuricemia and anti-gouty arthritis effects of the ethanol extract from Amomumvillosum Lour.

The incidence of hyperuricemia and gout has been increasing year by year, and it is showing a younger trend. However, the first-line drugs currently used for hyperuricemia and gouty arthritis have serious side effects that limit their clinical application. Amomum villosum Lour. has been widely used in China for thousands of years as a traditional medical and edible plant, and previous screening showed that the ethanol extract of Amomum villosum Lour. could effectively inhibit the activity of xanthine oxidase. Based on this discovery, this paper had achieved in-depth mechanism research. The results showed that the ethanol extract of Amomum villosum Lour. could treat hyperuricemia by reducing the production of uric acid via inhibition of xanthine oxidase and increasing the excretion of uric acid via regulation of urate transporters. Meanwhile, the extract also showed a certain protective effect on hepatic and renal damage caused by hyperuricemia. With the formation of extensive uric acid, gouty arthritis will be induced by the deposition of monosodium urate in the joint. The extract could also relieve the inflammation by reducing the expression of inflammatory cytokines. In conclusion, the extract deserves focused research and development as a potential medicine, health care product or supplemented food for the prevention and treatment of hyperuricemia and gouty arthritis.

Design, synthesis and bioevaluation of 1,2,4-thiadiazolidine-3,5-dione derivatives as potential GSK-3ß inhibitors for the treatment of Alzheimer's disease.

Tideglusib is a non-competitive GSK-3ß inhibitor which contain 1,2,4-thiadiazolidine-3,5-dione moiety, and now mainly used for progressive supranuclear palsy due to the lack of some primary cognitive endpoints and secondary endpoints in a phase IIb trail for Alzheimer's disease. Additionally, insufficient evidence exists to support that there are obvious covalent bonds between Tideglusib and GSK-3ß. Targeted covalent inhibition strategy could improve the binding efficiency, selectivity and duration of kinase inhibitors. Based on the above premise, two series of targeted compounds with acryloyl warheads were designed and synthesized. The kinase inhibitory activity of the selected compound 10a with better neuroprotective effect improved 2.7 fold than that of Tideglusib. After the preliminary screening of GSK-3ß inhibition and neuroprotective activity, the mechanism action of the selected compound 10a was investigated in vitro and in vivo. The results confirmed that 10a with excellent selectivity among the whole tested kinases could significantly reduce the expressions of APP and p-Tau via increasing the level of p-GSK-3ß. The pharmacodynamic assay in vivo showed that 10a could markedly improve the learning and memory functions in AD mice induced by AlCl3 combined with d-galactose. At the same time, the damage of hippocampal neurons in AD mice was obviously reduced. Accordingly, the introduction of acryloyl warheads could increase the GSK-3ß inhibitory activity of 1,2,4-thiadiazolidine-3,5-dione derivatives, and the selected compound 10a deserves further research as an effective GSK-3ß inhibitor for the potential treatment of AD.

Research on an Intelligent Identification and Classification Method of Complex Holes in Triangle Meshes for 3D Printing.

In triangular mesh models, the repair of complex hole poses a difficult problem, which always causes serious repair defects. Therefore, it is needed to develop an intelligent identification and classification method of complex holes to reduce repair difficulties. First, the topological structure of the complex hole is studied and all the holes are divided into single holes and continuous holes depending on whether there are intersection points. Second, to tackle the nesting and connecting of complex continuous holes, a decomposition method of multiply connected domains based on intersection points is proposed to partition or reconstruct complex continuous holes into single holes. Based on the different geometric structures, single holes are classified into five common hole types and a corresponding identification method of single holes is presented. Finally, an experiment is carried out to verify the repair quality and efficiency of the proposed method. Compared with Geomagic software, the proposed method can automatically identify and partition complex holes with fewer defects and similar efficiency. It can reduce the difficulties of repairing complex holes and enable the repair of complex holes based on existing methods. It is shown that the method can be applied to complex hole repair of 3D printing models without the participation of technicians.

An Intelligent Identification and Repair Method for Annular Holes in 3D Printing.

With the popularization of 3D printing in the consumer goods field, there is a specific type of hole named annular hole in the narrow features, surface bumps, or folded parts of products. The traditional triangular mesh repair method is not effective for such holes. The structural characteristics of the annular hole are analyzed in this research, and the definition and identification method for annular holes is presented through the shape and position relationship of two closed hole lines. To improve the repair efficiency and the applicability of the algorithm, the traditional hole repair method and process are ameliorated. A repair strategy of hole boundary stitching and filling, triangulation optimization, implicit surface construction based on Radial Basis Function, and surface integral deformation is adopted to achieve a smooth joint of the repaired hole surface with the original triangular mesh surface. The method can ensure surface smoothness and accuracy. Finally, two experiments are carried out to verify the repair quality and efficiency of our method. Compared with Geomagic software, the proposed method can automatically identify and repair annular holes with fewer defects and similar efficiency. Compared with a traditional hole repair method, the evaluation results demonstrate that the proposed method is much faster, and the repair quality is higher without the influences of human operations. It is shown that our method can be applied to annular hole repair of 3D printing models without the participation of technicians.

The role of miR-7 as a potential switch in the mouse hypothalamus-pituitary-ovary axis through regulation of gonadotropins.

The hypothalamus-pituitary-ovary (HPO) axis plays fundamental roles in female neuroendocrinology and reproduction. Pituitary gonadotropins are located in the center of this axis. Previous investigation suggested that miR-7 is closely linked with gonadotropins. However, the interaction between miR-7 and the HPO axis remains unclear. This study aims to determine whether and how miR-7 functions in this axis. A mouse ovariectomy model and mouse primary pituitary cells were used in this study. The results showed that miR-7 is localized to gonadotrophs and somatotrophs. miR-7 can inhibit the expression, synthesis and secretion of gonadotropins, but not growth hormones. Gonadotropin-releasing hormone (GnRH) has inhibitory effects on miR-7, while estrogen enhances miR-7 expression. miR-7 is vital for the pathway by which GnRH and estrogen regulate gonadotropins by targeting v-raf-leukemia viral oncogene 1 (Raf1). Together, these results indicate that miR-7 acts as a potential switch in the feedback loop of the HPO axis by regulating gonadotropins.

Second-order calibration serves as a remedial measure for the simultaneous determination of andrographolide and dehydroandrographolide in Andrographis paniculata and its preparations by HPLC without complete baseline separation.

In this work, high-performance liquid chromatography with diode array detection was applied for the simultaneous determination of andrographolide and dehydroandrographolide in Andrographis paniculata and its preparations. As a result of the incomplete baseline separation caused by complex backgrounds, the classical univariate calibration method failed to determine accurate contents of the analytes. On this occasion, chemometric second-order calibration based on the well-known alternating trilinear decomposition algorithm was then explored to serve as a post-experimental remedial tool to solve this problem. By using the intelligent "mathematical separation" of alternating trilinear decomposition, the peak areas of the analytes do not need to be directly measured and the predictive results become accurate. The contents of andrographolide and dehydroandrographolide were determined to be (7.95 ± 0.15) and (1.85 ± 0.02) µg/mL for Andrographis paniculata, (1.34 ± 0.01) and (5.53 ± 0.04) µg/mL for its preparations, which was in agreement with those obtained by a reference liquid chromatography with mass spectrometry method. This study showed the superiority of second-order calibration method over classical univariate calibration method for simultaneous determination of multi-analytes in complex samples. It also proved that second-order calibration may be a good choice for remedying incomplete baseline separation problem, with the accompanied reduction of experimental burden and toxic organic solvents as well as analysis time and cost.

A green chemometrics-assisted fluorimetric detection method for the direct and simultaneous determination of six polycyclic aromatic hydrocarbons in oil-field wastewaters.

Oil-field wastewaters contain high level of polycyclic aromatic hydrocarbons (PAHs), which have to be analyzed to assess the environmental effects before discharge. In this work, a green fluorimetric detection method that combines excitation-emission matrix (EEM) fluorescence with parallel factor analysis (PARAFAC) algorithm was firstly developed to achieve the direct and simultaneous determination of six U.S. EPA PAHs in two different kinds of complex oil-field wastewaters. Due to the distinctive "second-order advantage", neither time-consuming sample pretreatments nor toxic organic reagents were involved in the determination. By using the environment-friendly "mathematical separation" of PARAFAC, satisfactory quantitative results and reasonable spectral profiles for six PAHs were successfully extracted from the total EEM signals of oil-field wastewaters without need of chromatographic separation. The limits of detection of six PAHs were in the range of 0.09-0.72ngmL-1, and the average spiked recoveries were between (89.4±4.8)% and (109.1±5.8)%, with average relative predictive errors <2.93%. In order to further confirm the accuracy of the proposed method, the same batch oil-field wastewater samples were analyzed by the recognized GC-MS method. t-test demonstrated that no significant differences exist between the quantitative results of the two methods. Given the advantages of green, fast, low-cost and high-sensitivity, the proposed method is expected to be broadened as an appealing alternative method for multi-residue analysis of overlapped PAHs in complex wastewater samples.

Comparison of three-way and four-way calibration for the real-time quantitative analysis of drug hydrolysis in complex dynamic samples by excitation-emission matrix fluorescence.

Multiway calibration in combination with spectroscopic technique is an attractive tool for online or real-time monitoring of target analyte(s) in complex samples. However, how to choose a suitable multiway calibration method for the resolution of spectroscopic-kinetic data is a troubling problem in practical application. In this work, for the first time, three-way and four-way fluorescence-kinetic data arrays were generated during the real-time monitoring of the hydrolysis of irinotecan (CPT-11) in human plasma by excitation-emission matrix fluorescence. Alternating normalization-weighted error (ANWE) and alternating penalty trilinear decomposition (APTLD) were used as three-way calibration for the decomposition of the three-way kinetic data array, whereas alternating weighted residual constraint quadrilinear decomposition (AWRCQLD) and alternating penalty quadrilinear decomposition (APQLD) were applied as four-way calibration to the four-way kinetic data array. The quantitative results of the two kinds of calibration models were fully compared from the perspective of predicted real-time concentrations, spiked recoveries of initial concentration, and analytical figures of merit. The comparison study demonstrated that both three-way and four-way calibration models could achieve real-time quantitative analysis of the hydrolysis of CPT-11 in human plasma under certain conditions. However, it was also found that both of them possess some critical advantages and shortcomings during the process of dynamic analysis. The conclusions obtained in this paper can provide some helpful guidance for the reasonable selection of multiway calibration models to achieve the real-time quantitative analysis of target analyte(s) in complex dynamic systems.

EGF-induced urokinase plasminogen activator receptor promotes epithelial to mesenchymal transition in human gastric cancer cells.

Epidermal growth factor (EGF) signaling has been shown to induce epithelial to mesenchymal transition (EMT) in many types of cancer cells. However, the molecular mechanism of EGF-induced EMT in gastric cancer remains largely unknown. In the present study, we found that human gastric cancer cell lines SGC-7901 and BGC-823 underwent EMT phenotypic changes upon exposure to EGF. The induction of EMT was consistent with aggressive characteristics such as increased cell migration, invasion and clonogenic growth. Additionally, EGF stimulation also led to the upregulation of urokinase plasminogen activator receptor (uPAR) both at mRNA and protein levels. Knockdown of uPAR by siRNA significantly attenuated EMT induction by EGF in SGC-7901 and BGC-823 cells. Furthermore, EGF increased ERK1/2 activity and blocking ERK1/2 signaling with its inhibitor, U0126, markedly inhibited EGF-induced uPAR expression and consequently EMT. Collectively, the present study demonstrated that EGF induced aggressiveness of gastric cancer cells by activating EMT, which involved the activation of the ERK1/2 pathway and, subsequently, uPAR expression.