Reliable Analysis of the Interaction between Specific Ligands and Immobilized Beta-2-Adrenoceptor by Adsorption Energy Distribution.

Although a comparatively robust method, immobilized protein-based techniques have displayed limited precision and inconsistent results due to a lack of strategy for the accurate selection of drug adsorption models on the protein surface. We generated the adsorption data of three drugs on immobilized beta-2-adrenoceptor (ß2-AR) by frontal affinity chromatography-mass spectrometry (FAC-MS) and site-specific competitive FAC-MS. Using adsorption energy distribution (AED) calculations, we achieved the best adsorption models for the binding of salbutamol, terbutaline, and pseudoephedrine to immobilized ß2-AR. The Langmuir model proved to be desirable for describing the adsorptions of salbutamol and terbutaline on immobilized ß2-AR, while the bi-Langmuir model was favorable to characterize the adsorption of pseudoephedrine on the receptor. Relying on the accurate determination of association constants, we presented an efficient approach for ß2-AR ligand screening based on the loss of breakthrough time of an indicator drug caused by the inclusion of competitive drugs in the mobile phase. We concluded that the current strategy enables the reliable and accurate analysis of G protein-coupled receptor (GPCR)-drug interaction. The percentage change in the breakthrough time for drugs can provide useful information for estimating their binding affinity to the receptor. This approach builds a powerful platform for high-throughput ligand screening.

Target-directed screening of the bioactive compounds specifically binding to ß2-adrenoceptor in Semen brassicae by high-performance affinity chromatography.

The bioactive ingredients in Semen sinapis were rapidly screened by immobilized ß2-adrenoceptor (ß2-AR) and target-directed molecular docking. The methods involved the attachment of ß2-AR using any amino group in the receptor, the simultaneous separation and identification of the retention compounds by high-performance affinity chromatography; the binding mechanism of the interesting compound to the receptor was investigated by zonal elution and molecular docking. Sinapine in Semen sinapis was proved to be the bioactive compound that specifically binds to the immobilized receptor. The association constant of sinapine to ß2-AR was determined to be 1.36 × 10(5) M(-1) with a value of 1.27 × 10(-6) M for the number of binding sites. Ionic bond was believed to be the driving force during the interaction between sinapine and ß2-AR. It is possible to become a powerful alternative for rapid screening of bioactive compounds from a complex matrix such as traditional Chinese medicine and further investigation on the drug-receptor interaction.

Screening bioactive compounds from Ligusticum chuanxiong by high density immobilized human umbilical vein endothelial cells.

High throughput screening methodologies play a very important role in screening bioactive compounds from complex media. In this work, a new strategy for attaching cells onto amino microspheres using human umbilical vein endothelial cells (HUVECs) as a probe was developed. The immobilization depended on the specific affinity between integrin on the cells and the RGD peptide, which was coated on poly[oligo (ethylene glycol) methacrylate] by atom transfer radical polymerization. Validated application of the stationary phase was performed in the analysis of Ligusticum chuanxiong extraction by high performance affinity chromatography-mass spectrometry. Three compounds were screened as the bioactive compounds of Ligusticum chuanxiong. Two of them were identified as 3-butyl-hexahydroisobenzofuran-1(3H)-one and tetramethylpyrazine (TMP), whereas the other one remains indistinct. The association constant of vascular endothelial growth factor (VEGF) and TMP binding to VEGF receptor (VEGFR) on HUVECs were calculated to be (1.04 ± 0.08) × 10(11) M(-1) and (9.84 ± 1.11) × 10(8) M(-1) by zonal elution. Molecular docking showed that one hydrogen bond was formed between N atom of TMP and 3-N atom of imidazole group in histidine(223) of VEGFR. Both zonal elution and molecular docking indicated that TMP and VEGF bind to the same site of VEGFR on HUVECs. It is possible to become a promising tool for high throughput screening of the bioactive compounds binding to HUVECs through broad application of the stationary phase.

Knowledge, attitudes, and practices of human papillomavirus and self-sampling among adult women: a cross-sectional study.

Background: This study aimed to investigate the knowledge, attitude, and practice (KAP) of human papillomavirus (HPV) and self-sampling among adult women. Methods: The cross-sectional, questionnaire-based study included adult women at Shanghai Pudong Hospital from October 14, 2022, to March 31, 2023. The questionnaire contained demographic information, knowledge, attitude and practice dimensions. Factors associated with KAP and self-sampling were identified by multivariate logistic regression. Results: A total of 1843 valid questionnaires were collected. The average knowledge, attitude, and practice score was 10.09 ± 5.60, 26.76 ± 3.80, and 6.24 ± 2.20, respectively. Urban residents (estimate = 0.705, p < 0.001), suburban residents (estimate = 0.512, p < 0.001), as well as individuals with undergraduate degrees and higher (estimate = 0.535, p < 0.001), were associated with good knowledge, while individuals lacking a history of HPV infection (estimate = -0.461, p < 0.001) and married individuals (estimate = -0.185, p < 0.001) were less likely to have good knowledge. Higher knowledge scores (estimate = 0.087, p < 0.001) and individuals with undergraduate education and above (estimate = 1.570, p < 0.001) were associated with a positive attitude. Being married (estimate = 0.291, p = 0.049) was associated with good practice, whereas not engaging in sexual activity (estimate = -0.959, p < 0.001) or lacking a history of HPV infection (estimate = -0.499, p = 0.011) were associated with unfavorable practices. Minorities (OR = 2.787, p = 0.038) and individuals with multiple sexual partners (OR = 2.297 for two partners, OR = 2.767 for three or more partners, p = 0.020 and p = 0.022) were positively associated with self-sampling. However, higher knowledge (OR = 0.952, p = 0.026) and attitude scores (OR = 0.929, p = 0.015) were negatively associated with self-sampling. Conclusion: Demographic and behavioral factors significantly influenced KAP scores and self-sampling behaviors regarding HPV. Urban residency, higher education levels, positive attitudes, and minority status correlated with favorable outcomes, while factors like marriage and lack of sexual activity were associated with less favorable practices.

SMAD4 inhibits glycolysis in ovarian cancer through PI3K/AKT/HK2 signaling pathway by activating ARHGAP10.

BACKGROUND: ARHGAP10 is a tumor-suppressor gene related to ovarian cancer (OC) progression; however, its specific mechanism is unclear. AIMS: To investigate the effect of ARHGAP10 on OC cell migration, invasion, and glycolysis. METHODS AND RESULTS: Quantitative real-time PCR (qRT-PCR) quantified mRNA and protein expressions of AKT, p-AKT, HK2, and SMAD4 were tested by Western blot. EdU, Wound healing, and Transwell assay were utilized to evaluate OC cell proliferation, migration, and invasion. We used a Seahorse XF24 Extracellular Flux Analyzer to monitor cellular oxygen consumption rates (OCR) and extracellular acidification rates (ECAR). Chromatin immunoprecipitation (ChIP) was used to analyze the transcriptional regulation of ARHGAP10 by SMAD4. ARHGAP10 expression in OC tissues was detected by immunohistochemistry. Our results showed that ARHGAP10 expression was negatively related to lactate levels in human OC tissues. ARHGAP10 overexpression can inhibit the migration, proliferation, and invasion of OC cells, and this function can be blocked by 2-Deoxy-D-glucose. Moreover, we found that ARHGAP10 expression can be rescued with the AKT inhibitor LY294002. CONCLUSIONS: This study revealed that the antitumor effects of ARHGAP10 in vivo and in vitro possibly suppress oncogenic glycolysis through the PI3K/AKT/HK2-regulated glycolysis metabolism pathway.

Insulin reverses choriocarcinoma 5- fluorouracil resistance.

Choriocarcinoma (CC) is a gestational trophoblastic tumor secondary to a gravid or non-gravid pregnancy. It is characterized by rapid growth, high invasion, and high metastatic potential and chemotherapy resistance that significantly affect survival rate of CC patients. Insulin is implicated in alleviation of chemotherapy resistance in CC. However, the mechanism of reversing resistance in CC has not been explored. Our purpose was to explore insulin effect on 5-fluorouracil (5-FU) resistance in CC and elucidate its potential mechanism in vitro and in vivo. CKK-8, colony formation, Transwell, and flow cytometry were used to detect the effect of insulin on 5-FU resistance in CC cells JEG-3 and JARS. Xenograft mice were used to evaluate the effect of insulin on 5-FU resistance. Results showed that insulin combined with 5-FU suppressed cell viability by 30% in JEG-3 and 43% in JAR compared with 5-FU alone in 72 h. What's more, insulin combined with 5-FU promoted cell apoptosis, inhibited cell proliferation, migration, and phosphorylation of survivin at residue threonine 34 (Thr34) and drug resistance-related proteins, P-GP and MRP1 levels (p < 0.05). In vivo experiment showed Insulin combined with 5-FU suppressed tumor volume by 35% compared with 5-FU alone and 73% compared with control in CC xenograft mice. In summary, the findings of this study show that insulin reversed chemoresistance of CC cells to 5-FU by inhibiting phosphorylation of survivin. Development of a therapeutic strategy that combines insulin with the chemotherapeutic agent 5-FU has a great potential in improving survival of CC patients.

Characterization of the heterogeneous adsorption of three drugs on immobilized bovine serum albumin by adsorption energy distribution.

Characterization of the heterogeneity of a protein surface is important for understanding the binding mechanism of a drug to the protein. A systematic methodology of integrated adsorption energy distribution (AED) calculation with the Scatchard plot was used to characterize the heterogeneous binding of drugs to bovine serum albumin (BSA). Frontal affinity chromatography (FAC) was applied to generate the adsorption data of three drugs on the immobilized BSA column. The concave Scatchard plots cannot distinguish the heterogeneous model between Toth and bi-Langmuir. The calculation of AED profiles allowed the accurate selection of adsorption models to reveal the physical sense of the drugs. Warfarin-BSA complex proved to be the bi-Langmuir model with association constants of 6.6 × 105 M-1 and 2.4 × 103 M-1, respectively. These results were highly consistent with traditional frontal analysis, ultrafiltration, and dynamic dialysis. Applying the AED related method, we achieved multiple and single kinds of binding sites for ephedrine-BSA and L-tryptophan-BSA complexes. Site-specific competitive studies exhibited non-competitive binding of ephedrine with warfarin or L-tryptophan on BSA, underlining that the location of ephedrine binding sites in the subdomain IIIB of BSA. This method permits an accurate heterogeneous characterization of drugs on a protein surface and has great potential in the reliable drug-protein interaction analysis.

Rapid screening and identification of bioactive compounds specifically binding to beta 2-adrenoceptor from San-ao decoction using affinity magnetic fine particles coupled with high-performance liquid chromatography-mass spectrometry.

BACKGROUND: San-ao decoction (SAD) has been widely used in Chinese medicine against respiratory diseases, such as asthma and rhinallergosis. The bioactive compounds for such pharmacological action remain unknown. METHODS: We developed a methodology to isolate the bioactive compounds of SAD. The assay involved the immobilization of beta 2-adrenoceptor (ß 2-AR) onto magnetic fine particles, the capture of target compounds by the immobilized receptor, the identification of the receptor bound compounds by reversed-phase high-performance liquid chromatography coupled with tandem mass spectrometry. RESULTS: Vicenin, shaftoside, isoshaftoside, liquiritin apioside and isoliquiritin apioside were identified as ß 2-AR ligands in SAD extract. The binding of these compounds to ß 2-AR occurred on serine169, serine170 and phenylalanine256 of the receptor. CONCLUSIONS: The developed methodology has high stability and specificity for recognizing and isolating target compounds. It is an alternative method for rapidly screening bioactive compounds of immobilized receptor from Chinese prescriptions.

Binding kinetics of five drugs to beta2-adrenoceptor using peak profiling method and nonlinear chromatography.

Investigations of drug-protein interactions have advanced our knowledge of ways to design more rational drugs. In addition to extensive thermodynamic studies, ongoing works are needed to enhance the exploration of drug-protein binding kinetics. In this work, the beta2-adrenoceptor (ß2-AR) was immobilized on N, N'-carbonyldiimidazole activated amino polystyrene microspheres to prepare an affinity column (4.6 mm × 5.0 cm, 8 µm). The ß2-AR column was utilized to determine the binding kinetics of five drugs to the receptor. Introducing peak profiling method into this receptor chromatographic analysis, we determined the dissociation rate constants (kd) of salbutamol, terbutaline, methoxyphenamine, isoprenaline hydrochloride and ephedrine hydrochloride to ß2-AR to be 15 (±1), 22 (±1), 3.3 (±0.2), 2.3 (±0.2) and 2.1 (±0.1) s-1, respectively. The employment of nonlinear chromatography (NLC) in this case exhibited the same rank order of kd values for the five drugs bound to ß2-AR. We confirmed that both the peak profiling method and NLC were capable of routine measurement of receptor-drug binding kinetics. Compared with the peak profiling method, NLC was advantageous in the simultaneous assessment of the kinetic and apparent thermodynamic parameters. It will become a powerful method for high throughput drug-receptor interaction analysis.

Tanshinol borneol ester on nanostructured lipid carriers has longer brain and systemic effector retention and better antioxidant activity in vivo.

BACKGROUND: Tanshinol borneol ester (DBZ) is a hybrid of danshensu (DSS) and borneol and has anti-ischemic activity in animals. However, its low water solubility and short half-life limit its clinical application. METHODS: We prepared polyethylene glycol (PEG)-modified and DBZ-loaded nanostructured lipid carriers (DBZ-PEG-NLC) and DBZ-NLC, and examined their physical characteristics, such as particle size, zeta potential, entrapment efficiency and drug loading. The in vitro stability and pharmacokinetics in rats as well as antioxidant activity of DBZ-PEG-NLC and DBZ-NLC in a C57BL/6 mouse model of ischemia/reperfusion-related brain injury were investigated. The levels of DBZ and its hydrolyzed DSS in rat plasma and brain microdialysates were determined by liquid chromatography-mass spectroscopy/mass spectroscopy analysis. RESULTS: We found that the mean particle size and entrapment efficacy of DBZ-PEG-NLC were similar to that of DBZ-NLC. The DBZ-PEG-NLC, like DBZ-NLC, released DBZ in a biphasic manner with initially burst release and then prolonged slow release in vitro. Intravenous injection of DBZ-PEG-NLC resulted in significantly higher levels and longer retention periods of DBZ and DSS in plasma and the brains than DBZ-NLC and DBZ in rats. Finally, treatment with DBZ-PEG-NLC achieved a better antioxidant activity than DBZ or DBZ-NLC in mouse model of ischemia/reperfusion by reducing the levels of brain malondialdehyde, but increasing the levels of brain superoxide dismutase and glutathione. CONCLUSION: DBZ-PEG-NLC is a preferable option to deliver DBZ for sustainable release of DSS and borneol in vivo, and may serve as a promising drug for effective therapy of ischemic cardiovascular and cerebrovascular diseases.