Latest ArticlesJasmonic acid (JA) is an important signal molecule involved in plant resistance, and allene oxide synthase (AOS) is a key enzyme in the biosynthesis of jasmonates. In this study, a full-length cDNA of AsAOS1 gene was cloned from Aquilaria sinensis. Meanwhile, the sequence analysis, prokaryotic expression, purification, tissue-specific expression analysis and expression analysis under different abiotic stresses and hormone treatments were performed. The open reading frame (ORF) of AsAOS1 gene was 1 575 bp, encoding a protein of 524 amino acid residues, with a predicted molecular mass of 58.70 kDa. AsAOS1 protein possessed the conserved sequences of cytochrome P450 (CYP450). The phylogenetic analysis indicated that AsAOS1 protein had the highest level of homology with AOS protein of Citrus sinensis. The recombinant AsAOS1 protein was successfully expressed in Escherichia coli BL21(DE3) cells using the prokaryotic expression vector pET28a-AsAOS1 and the recombinant AsAOS1 was purified by Ni2+ affinity chromatography. Expression analysis results in different tissues showed that AsAOS1 was primarily observed in stems, and then roots, followed by leaves. AsAOS1 transcript level was significantly induced after 12 h treatment of NaCl, cold temperature and CdCl2. Furthermore, AsAOS1 expression level was enhanced upon methyl jasmonate (MeJA), salicylic acid (SA) and abscisic acid (ABA) treatment. However, mannitol and gibberellin (GA3) treatments had little influence on the expression level of AsAOS1. These results provides valuable insights into the role of JA in the mechanism of agarwood formation and plant resistance.
Nimodipine is a selective calcium channel antagonist of cerebral vessels smooth muscle and also has polymorphs. It hasn't been reported that different crystal forms influence the metabolism process in huge animals like rhesus monkeys in vivo. This article may provide reference in the control of the quality of nimodipine and quality consistency evaluation. The powder X-ray diffraction (PXRD) method was used to identify different crystal forms and the dissolution test in vitro was used to detect the dissolution. The LC-MS method of assay nimodipine in rhesus monkey plasm was established to determine pharmacokinetics characters of different tablets from different crystal forms in rhesus monkey in vivo. As a result, the tablets inherit difference crystal forms and the dissolution of reference tablets is 1.3% higher than crystal tablets. However, the maximal blood concentration (Cmax) of crystal tablet was 37.3% higher than reference tablet and AUC of crystal tablet was 29.8% higher than reference tablet. After administrated 2.5 mg·kg-1 orally, calculated pharmacokinetics characters were observed as following:Cmax was 381.4 ±327.3 and 178.0 ±214.8 μg·L-1; AUC0-t was 853.1 ±500.7 and 646.5 ±430.3 μg·L-1·h respectively. The serum concentration result of different nimodipine tablets in rhesus monkeys in vivo suggests that polymorphs has a significantly distinction, which points out that controlling the crystal forms of nimodipine is essential to ensure the therapeutic efficacy. It is essential to execute quality consistency evaluation.
Photo-sensitive reactive oxygen species (ROS) responsive liposomes loaded with 1, 4, 8, 11, 15, 18, 22, 25-octabutoxypalladium phthalocyanine[PdPC(OBu)8] and doxorubicin hydrochloride (DOX) (LPD) were prepared by (NH4)2SO4-gradient method. LPD was characterized with transmission electron microscopy (TEM), dynamic light scattering particle size, zeta potentials, photo-sensitive ROS-responsive DOX release behaviors and the serum stability in vitro. LPD cytotoxicity, DOX uptake and singlet oxygen production in MCF-7 cells were evaluated. The results showed that the particle size of LPD was (169.3 ±1.2) nm, PDI of LPD was 0.198 ±0.003 and zeta potentials of LPD was (-39.8 ±0.8) mV. The accumulated release of DOX reached 95.5% in 5 min under 730 nm laser irradiation (300 mW·cm-2). The DOX uptake of liposome was increased and 1O2 was generated. The half inhibition concentration (IC50) of DOX in LPD with irradiation group was decreased by 85.7% and no irradiation group was decreased by 67.9% compared with free DOX group in MCF-7 cells. Therefore, photo-sensitive ROS-responsive liposomes would be a promising drug delivery system for tumor therapy.
The aim of the experiments is to screen human single-chain variable fragment (scFv) targeting glypican 3 from phage display library, and analyze its biological activity. After several rounds of panning, the binders with high affinity were obtained through phage ELISA and IMGT analysis. The desired scFv gene was then ligated with pET-22b vector yielding recombinant plasmids, which was then introduced into E. coli Rosetta (DE3). Soluble scFv protein was expressed and further purified using Ni2+ affinity chromatography. The purified proteins were identified by SDS-PAGE and Western blot. Subsequently, the affinity and cell based binding activity were measured using Surface Plasmon Resonance (SPR) and flow cytometry assay, separately. Four enriched sequences with relatively high binding affinity were found (1F7, 1D7, 1D4 and 1B10). We also found that 1F7 scFv showed better targeting ability and higher affinity. The scFv could pave the way for new immunotherapies, such as bispecific anitbody, antibody-drug conjugate and chimeric antigen receptor T-cell immunotherapy cell, etc.
A droplet microfluidic chip system was developed for drug screening against Candida albicans. The microfluidic chip was designed and prepared for the formation of droplets. Alamar blue was selected as an indicator for its characteristic of fluorescence mission in live cells. Four antifungal drugs (amphotericin B, caspofungin, 5-fluorocytosine, terbinafine) and a new drug (iodiconazole) were selected as model drugs to test the microfluidic chip approach. At the same time, 96-well microplate method was performed to verify the applicability of the chip method. The results showed that the developed droplet microfluidic chip platform was able to complete the antifungal susceptibility test within 2 h. In comparison with the 96-well microplate method, the microfluidic chip method showed a consistence of 100% with regard to the minimum inhibition concentrations and less reagent consumption. The new droplet microfluidic chip method is simple, rapid and suitable for rapid screening of antifungal drugs.
The aim of this study is to establish the in vitro methods for the study of induction and inhibition on CYP450 by drugs, and to validate the analytical method and incubation system. A method for the simultaneous determination of eight metabolites of seven subtypes of CYP450 enzymes probe substrates in human liver microsomes (HLM) was established and validated. The incubation system was optimized to confirm the incubation time and protein concentration of HLM, the enzyme activity of seven subtypes of CYP450 enzymes in HLM was determined, and the inhibition effects on each CYP450s were checked by positive controls. The method for the simultaneous determination of three metabolites of subtypes of CYP450 enzymes was established and validated in human primary cultured hepatocytes (HPCH) using the incubation medium. The enzyme activity of three subtypes of CYP450 enzymes in HPCH was determined, and the total RNA was extracted from HPCH after incubation. The expression of CYP450 enzymes were measured by Taqman fluorescence probe method. The induction effects on each CYP450s were examined using the positive controls. The established methods for the determination of metabolites of probe substrates were fully validated, and the results were conformed to the requirements of bioanalytical method validation. The induction and inhibition effects on each CYP450s were checked by positive controls. The established in vitro methods for the study of drug induction and inhibition on CYP450 were simple and reliable, which could be used in the investigation of enzyme induction or inhibition properties of new drug candidates and to evaluation the metabolic interactions of concomitant medication in clinical.
Selenium (molecular weight 78.96), is a necessary non-metallic trace elements. In recent years, more and more studies have found that selenium is closely related to human disease and could not be ignored. In this paper, we elucidate the in vivo absorption and metabolism of selenium; the active substance-selenoprotein P and so on; the correlation between selenium and pathogenesis of various diseases such as cardiovascular disease, AD/PD neurodegenerative diseases and cancer, etc. The aim is to achieve a more comprehensive understanding of selenium, and to research the in vivo process and the biological effects of selenium. At the same time, selenoproteins and related mechanisms might also be a new target for drug research and discovery.
In the past 20 years, tumor immunotherapy has made a significant progress in tumor inhibition effects in both laboratory studies and clinical trails. In the immune response to tumor, effective antitumor immunity is induced during the tumor progress; long-term monitoring of the tumor would be achieved through the immune memory, reducing the possibility of tumor recurrence. In the immune treatment strategies, a focus is delivery of therapeutic immune regulators with nanocarriers. It has been demonstrated that due to the special physical and chemical properties, nanocarriers are easily internalized by immune cells, which regulate the immune responses and effectively induce anti-tumor immune cascade to achieve the tumor inhibition effect. In this paper, we will discuss the progress of nanocarrier-mediated antitumor immunotherapy in recent years.
With the development of antibody manufacturing technology and improvement in new drug research and development (R&D) capabilities in domestic industry, more and more innovative antibody-based drugs were registered at the Investigational New Drug (IND). This type of drugs could be divided into three categories:new sequence antibodies (biobetter or new target antibodies), bispecific antibodies (or antibody cocktails), and antibody drug conjugates. Comparing with biosimilar antibodies, the innovative antibodies R&D was characterized by some significant features including "innovation", "clinical phase-appropriate" and "progressing". The minimum requirements of Chemical, Manufacturing and Control (CMC) content for innovative antibodies were obviously different from biosimilar antibodies. Here, the recent progress of antibody engineering and IND date of innovative antibodies in domestic are summarized. The general regulatory requirement and special considerations for representative innovative antibodies were proposed. Some common problems concerning innovative antibodies R&D are discussed.
Ferroptosis is a novel type of cell death which induced by iron-dependent lipid peroxidation accumulation. This type of cell death is significantly different from other cell death in terms of morphology, genetics and biochemistry. It has been reported that ferroptosis is involved in a variety of human diseases, particularly in liver diseases. Therefore, screening and studying of inhibitors or activators of ferroptosis may provide novel strategies for prevention and treatment of liver diseases. This review provides the biological characteristics and regulatory signaling pathways of ferroptosis, as well as the relationship between ferroptosis and liver diseases, which will contribute to new insight into the pathogenesis of liver diseases.