Establishment of a pharmacokinetics and pharmacodynamics model of Schisandra lignans against hippocampal neurotransmitters in AD rats based on microdi-alysis liquid chromatography-mass spectrometry.

Objective: Our previous studies substantiated that the biological activity of Schisandra chinensis lignans during the treatment of Alzheimer's disease (AD) was mediated by neurotransmitter levels, and 15 of its active components were identified. However, the pharmacokinetic and pharmacodynamic relationship of Schisandra chinensis lignans has been less studied. The objective of this study was to investigate the relationship between the pharmacokinetics and pharmacodynamics of Schisandra chinensis lignans in the treatment of AD, and to establish a pharmacokinetic-pharmacodynamic (PK-PD) model. Methods and Results: Herein, we established a microdialysis-ultra performance liquid chromatography-triple quadruple mass spectrometry (MD-LC-TQ-MS) technique that could simultaneously and continuously collect and quantitatively analyze the active compounds and neurotransmitters related to the therapeutic effects of Schisandra chinensis in awake AD rats. Eight lignans were detected in the hippocampus, and a PK-PD model was established. The fitted curves highlighted a temporal lag between the maximum drug concentration and the peak drug effect. Following treatment, the levels of four neurotransmitters tended to converge with those observed in the sham operation group. Conclusion: By establishing a comprehensive concentration-time-effect relationship for Schisandra chinensis lignans in AD treatment, our study provides novel insights into the in vivo effects of these lignans in AD rats.

Proteomics and Biochemical Analyses of Secreted Proteins Revealed a Novel Mechanism by Which ADAM12S Regulates the Migration of Gastric Cancer Cells.

Gastric cancer is one of the cancers with the highest morbidity and mortality. Although several therapeutic approaches have been developed to treat this disease, the overall survival rate is still very low due to metastasis, drug resistance, and so forth. Therefore, it is necessary to discover new regulatory molecules and signaling pathways that modulate the metastasis of gastric cancer cells. A Disintegrin And Metalloprotease 12 (ADAM12) was highly expressed in gastric cancer tissues and presented in the patient urine. However, it is unclear whether and how ADAM12 regulates the migration of gastric cancer cells. In this work, we used the secretome protein enrichment with click sugars (SPECS) method to purify the secreted glycosylated proteins and performed quantitative proteomics to identify the secreted proteins that were differentially regulated by ADAM12S, the short and secreted form of ADAM12. Our proteomic and biochemical analyses revealed that ADAM12S upregulated the cell surface glycoprotein CD146, a cell adhesion molecule and melanoma marker, which was dependent on the catalytic residue of ADAM12S. Furthermore, we discovered that the ADAM12S-enhanced migration of gastric cancer cells was, at least partially, mediated by CD146. This work may help to evaluate whether ADAM12 could be a potential therapeutic target for the treatment of gastric cancer patients.

SILAC Quantitative Proteomics and Biochemical Analyses Reveal a Novel Molecular Mechanism by Which ADAM12S Promotes the Proliferation, Migration, and Invasion of Small Cell Lung Cancer Cells through Upregulating Hexokinase 1.

Small cell lung cancer (SCLC) accounts for ∼14% of total lung cancer, which is the worldwide leading cause of morbidity and mortality in cancer. Although SCLC can be treated with chemotherapy and radiotherapy, its 5 year survival rate is still below 7%. Therefore, it is essential to discover new molecules and elucidate the underlying mechanisms modulating the tumorigenesis and metastasis of SCLC for the unmet medical needs. The secreted form of A Disintegrin And Metalloproteinase 12 (ADAM12S) is highly expressed in SCLC and promotes the proliferation, migration, and invasion of SCLC cells. However, the underlying molecular mechanism is still elusive. Using stable isotope labeling by amino acids in cell culture (SILAC)-based quantitative proteomics, we identify 82 ADAM12S-regulated proteins in an SCLC cell line. Our proteomics and biochemical analyses discover that ADAM12S overexpression elevates while ADAM12 knockdown reduces the rate-limiting enzyme hexokinase 1 (HK1) in glycolysis. Through bioinformatics analyses, genetic manipulation, and in vitro assays, we further reveal that ADAM12S promotes the proliferation, colony formation, migration, and invasion of SCLC cells through upregulating HK1. This work links ADAM12S to glucose metabolic pathways in its attribution to the tumorigenesis and metastasis of SCLC cells and might provide valuable information for the exploration of therapeutic intervention for SCLC.