Chalcone isomerases (CHIs) play an essential role in the biosynthesis of flavonoids important in plant self-defense. Based on the transcriptome data of Aquilaria sinensis Calli, a full-length cDNA sequence of CHI1 (termed as AsCHI1) was cloned by reverse transcription PCR. AsCHI1 contains a complete open frame (ORF) of 654 bp. The deduced protein is composed of 217 amino acids, with a predicted molecular weight of 23.11 kDa. The sequence alignment and phylogenetic analysis revealed that AsCHI1 has conserved most of the active site residues in type I CHIs, indicating a close relationship with the CHI from Gossypium hirsutum. The recombinant AsCHI1 protein was obtained by heterologous expression of AsCHI1 in E. coli BL21(DE3). The purified AsCHI1 protein exhibited CHI activity by catalyzing the production of naringenin from naringenin chalcone. Remarkably, AsCHI1 expression in A. sinensis Calli treated with various abiotic stresses including salt, mannitol, cold, and heavy metals could be markedly increased, and plant hormones such as abscisic acid (ABA), gibberellin (GA3), and salicylic acid (SA) could also increase the expression of AsCHI1, suggesting that AsCHI1 might play an important role in plant self-defense. The results expand our understanding of the biosynthesis of flavonoids in A. sinensis and give further insight into the defensive responses of A. sinensis to abiotic and biotic stresses.

Transporters have a great influence on the transportation and distribution of drugs in the body. On the one hand, solute carrier transporters could transport drugs into tissues and organs, which may improve the oral bioavailability or change the tissue-distribution of the drugs. On the other hand, the ATP-binding cassette could pump some drugs out of the cell, which decreases the intracellular drug concentrations and leads to drug resistance.This paper summarizes the distribution, substrate characteristics and drug design strategies of several important drug transporters, such as improving bioavailability by prodrug design, introducing acid group to improve hepatic selectivity and adjusting the polarity of compounds to decrease efflux ratio.

Puerarin(PUE), as an isoflavone component, has a wide range of pharmacological activities, while its poorly aqueous solubility limits the development of solid oral dosage forms. In this study, PUE along with nicotinamide(NIC) were prepared into the coamorphous system by solvent-evaporation method and characterized by powder X-ray diffraction(PXRD), differential scanning calorimetry(DSC) and Fourier transform infrared spectroscopy(FT-IR). In addition, its dissolution behavior and solubilization mechanism were also investigated.PUE-NIC coamorphous was a single homogeneous binary system, with a single glass transition temperature at 35.1 ℃. In comparison to crystalline PUE, during the dissolution process, coamorphous PUE-NIC not only exhibited the "liquid-liquid phase separation"(LLPS) phenomenon, but the formation of A_p type complexation(1∶1 and 1∶2)between PUE and NIC molecules was also verified, which significantly improved the solubility of PUE and prolonged the supersaturation time, and would benefit its absorption.

We investigated the inhibitory effect and mechanism of action of bruceantin (BCT) on the proliferation, invasion and migration of non-small cell lung cancer (NSCLC) cells. The cytotoxic activity of BCT was measured by MTT assay; a colony forming assay, wound healing assay, and a Transwell assay were used to investigate the anti-proliferative, anti-migration, and anti-invasion effects, respectively; immunoblotting and RT-qPCR were used to detect the expression of related proteins, miRNA, and mRNA, respectively, that were involved in cell proliferation, migration, and invasion. Two gene prediction websites were used to predict the downstream target gene of miRNA. Our results show that BCT has a potent cytotoxic effect on NSCLC cell lines, with a half maximal inhibitory concentration (IC₅₀) of BCT against H1299, PC-9, and A549 of 0.12 ± 0.02, 0.31 ± 0.20, and 2.07 ± 0.70 μmol·L^-1, respectively. When H1299 cells were treated with 0.03, 0.15, and 0.75 μmol·L^-1 BCT for 24 h, the proliferation, migration, and invasive ability were inhibited in a concentration-dependent manner. It is worth noting that the expression level of miRNAs related to cell migration and invasion, such as miR-29a-3p, miR-21-3p, miR-183-5p, and miR-34b-5p increased with the concentration of BCT, especially for miR-29a-3p. Using the two gene prediction websites, we predict that integrin β1 (ITGB1) may be the target gene of miR-29a-3p; immunoblot results further show that a variety of proteins related to cell proliferation, migration, and invasion, such as various proteins of the integrin family, β-catenin, p-Src, and vascular endothelial growth factor, all decreased in a concentration-dependent manner, among which the reduction of ITGB1 protein was the most obvious. RT-qPCR results showed that there was no change in ITGB1 mRNA expression. We speculate that BCT might inhibit the expression of ITGB1 protein by up-regulating miR-29a-3p independent of its mRNA level. The in-depth mechanism needs to be further explored. This study suggests that BCT has the potential for further development in the treatment of NSCLC.

During growth and progression, the microenvironment of tumors suffers a series of abnormal characteristics, which include hypoxia, acid pH, increased oxidative stress, excess glutathione(GSH), as well as certain overexpressed enzymes. Although affect or limit the cancer therapeutic outcomes, these factors provide possible approaches to strategies for cancer detection and novel therapy at the same time. Recently, based on these properties of the tumor microenvironment(TME), various kinds of responsive nano-platforms have been continuously developed and applied in cancer theranostics preliminarily. Thus, this review would introduce the typical features of TME firstly, then detailly summarize the design principles and research progress of corresponding hypoxiaresponsive, pH-responsive, redox-responsive, enzyme-responsive, dual-responsive and multi-responsive nanoplatforms. Finally, the challenges and the perspectives of the TME-responsive nano-platforms are briefly discussed.

Nanoparticles have better applicability in the detection, treatment of cancer and various difficult diseases, but mononuclear phagocytosis system can seriously shorten the time of nanoparticles in vivo circulation, reduce the drug efficacy. The protein crown formed on the surface of the nanoparticle after entering the body can change its surface properties, interfere with the recognition of phagocytes, and thus affect its circulation time in vivo.This article outlines the general composition and formation process of protein crowns. It also summarizes the influence of the physical and chemical properties of nanoparticles, such as particle size, surface charge, hydrophilicity and surface materials on the formation of protein crowns. The protein crown affects the circulation of nanoparticles in vivo, mainly because the adsorbed opsonic protein promotes cell phagocytosis. Therefore, we also introduce the method of using protein crowns to promote the long circulation of nanoparticles in vivo. By designing appropriate physical and chemical properties, surface modification, and directed design of protein crowns, the adsorption of proteins on the surface of nanoparticles can be reduced. Therefore, it can reduce the clearance of nanoparticles in the mononuclear phagocytic system(mainly the phagocytes of the liver and spleen), and achieve the goal of long circulation of nanoparticles in the body.

The bioactivity of a working reference standard was determined by replicate bioassays with calibration against a primary reference standard. In this study the number of bioassay replicates needed for calibration first was calculated theoretically, and if the mean value of the experimental bioassay replicates fell within the predefined bioactivity level the bioactivity of the working reference was defined as 100%. Our results showed that when the total intermediate precision of the bioassay method was at 11.66% and the predefined bioactivity level was set at 95%-105% with a confidence level of 95%, 21 bioassay replicates should be carried out for calibration.The average value of the 22 experimental bioassay replicates was 101.96%, so the bioactivity of the working reference standard was consistent with that of the primary reference standard at 100%. The results suggest that a strategy of first calculating the number of bioassay replicates needed for calibration and then determining whether the resulting experimental mean value is within the predefined bioactivity level will be of value to the biopharmaceutical industry.

Protein kinases are intimately involved in the pathogenesis of many diseases such as cancer, inflammation, and autoimmune and neurological diseases. Therefore, kinases have been widely studied as drug targets over the past three decades. As of April, 2020, the FDA had approved 59 small molecule kinase inhibitors(SMKIs)in the emerging field of targeted drug therapy. This paper focuses on the biochemistry and pharmacology of these59 SMKIs and 121 SMKIs for which structures can be retrieved and that are now in phase Ⅱ and Ⅲ clinical trials.In addition, this paper also conducts a simple analysis of several popular targets and their inhibitors.

Osteoprotegerin(OPG), secreted by osteoblasts, is a marker of bone turnover. OPG can inhibit osteoclastic differentiation by binding receptor activator of nuclear factor-κB ligand(RANKL). In this study, we found that rutaecarpine(RUT) had the up-regulating OPG activity, and it could significantly increase OPG protein levels in both mouse embryonic osteogenic precursor MC3 T3-E1 and human osteosarcoma U-2OS cells. Osteoblastogenic differentiation calcified nodules staining results showed that RUT significantly promoted the osteogenic differentiation of MC3 T3-E1 cells. Osteoclastic differentiation tartrate resistant acid phosphatase(TRAP) staining results showed that RUT obviously inhibited the osteoclast differentiation of mouse macrophages RAW264.7 induced by RANKL. In vivo studies showed that low-dose RUT group(5 mg·kg^-1·day^-1) and high-dose RUT group(45 mg·kg^-1·day^-1) treatments for 3 months significantly increased bone density in ovariectomized(OVX) rats; calcein double labeling experiment and toluidine blue staining results indicated that low-dose RUT group promoted bone formation and decreased bone loss in vivo; immunohistochemistry results showed that low-dose RUT group increased the expression of OPG in rat femur. All animal procedures were performed in accordance with the regulations of the Institutional Animal Care and Use Committee of Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences. In summary, this study demonstrated that RUT could up-regulate OPG expression and had promoting osteoblastic differentiation and inhibiting osteoclastic differentiation effects in vitro and in vivo.

Alzheimer's disease(AD) is a neurodegenerative disease characterized by memory loss and cognitive impairment. To date, however, no disease-modifying strategies to prevent or cure AD exist. Synapses are involved in the connection of neurons and present as the key component for the memory and other neural activities. Synapse loss is a critical hallmark of AD pathology. In brain, glia cells, including microglia and astrocytes, are a group of highly specific cell types other than neurons. Microglia and astrocytes play a key role in maintaining the healthy neural circuit and regulating synaptic plasticity. Under development and physiological conditions, glial cells contribute to construct and maintain mature central neural networks via synaptic pruning. However, during AD pathogenesis, glial cells engulf synapses excessively, which leads to synapse loss, neuronal dysfunction, and cognitive impairment. Here, we review recent advances in our understanding of the underlying mechanisms for glia-mediated synaptic pruning in AD, and provide a novel strategy for the development of AD drugs.