Latest ArticlesPlant flowering regulation is an important mechanism to response to environmental stress. Heat shock protein 70 family is one of the main molecular chaperones to resist stress; miRNA can be used as a negative regulator to participate in post-transcriptional gene in flowering network. In this paper, we obtained an Hsp70 gene from Lonicera japonica transcriptome and combined with Lonicera japonica miRNA library to obtain a novel miRNA that may target Hsp70 gene through bioinformatics method. Bioinformatics and expression during different flowering stages of the obtained Hsp70 gene and miRNA were analyzed. Phylogenetic tree showed that the obtained Hsp70 gene was clustered with Hsp110 subfamily in Oryza sativa and Arabidopis thaliana. The prediction of miRNA secondary structure showed its stable structure and high reliability. The binding site map showed that there were two base mismatches between sequences of miRNA and Hsp70 gene. The expression analysis showed that the expression of Hsp70 and miRNA in different flowering stages had opposite trends, indicating that miRNA might regulate Hsp70 to participate in the flowering stages of Lonicera japonica. This study provided new ideas for Lonicera japonica flowering regulation and response to environmental stress mechanisms.
Dammarenediol-Ⅱ is an important precursor in the biosynthesis pathway of ginsenosides which are the main active components of Panax quinquefolius and Panax ginseng. For constructing a dammarenediol- Ⅱ-producing cell factory, the triterpenoid precursors of yeast are improved significantly by the modular pathway engineering strategy on the basis of an MVA optimized strain. The strain overexpressing Salvia miltiorrhiza SmFPS and Arabidopsis thaliana AtSQS2 could yield 67.4 mg·g-1 squalene, accounting for about 6.74% of cell dry weight. In our further work, an Arabidopsis thaliana 2, 3-oxidosqualene synthase AtSQE2 was found to be able to increase the downstream lanosterol yield by 22-fold, reaching 47.9 mg·g-1. Then, regulating dammarenediol-Ⅱ synthase gene expression, using anti-sense RNA technology for regulation of ERG7 in the ergosterol pathway, and optimizing fermentation process were successively performed. Finally, the synthesis flux of triterpenes was increased to 10 g·L-1 for the first time, and we constructed an efficient cell factory that can produce 15 g·L-1 dammarenediol-Ⅱ, which lays a solid foundation of industrial synthesis of dammarane-type ginsenosides.
Selectivity of drug action is a determinant for wide therapeutic window and less adverse response. From the viewpoint of molecular structure the conception and strategy of drug design are mainly embodied in raising selectivity. For the target-based drug discovery it is crucial to precisely obliterate detrimental targets in dimension of time and space, so as to efficaciously translate the in vitro active compounds into in vivo therapeutic medicines. To realize this translation drug molecules must be accurately transported to and destroy the harmful targets. To this end, chemical structures of drugs must be manipulated in multiple dimensions. This article attempts to concisely describe several kinds of bifunctional molecules for raising selectivity from the standpoint of medicinal chemistry. The bifunctionality of antibody-drug conjugates (ADCs) involves in the guidance and carrier of the antibody to guide ADC and reach to target cells, and simultaneously injury quality of the toxin moiety of ADC interacts with and destroys targets. Based upon target 3D structures design of irreversible inhibitors consist in connecting an appropriate electrophilic moiety to a well-defined ligand to endow the molecule with an additional ability to covalently bond to a specific amino acid residue. Hydrophobic tag (HyT), proteosis-targeting chimera (PROTAC), and degradation tag (dTAG) are new developed technologies, which are structurally characterized by bifunctionality, and mechanistically these compounds are capable of recruiting protein of interest (POI), inducing protein-protein interaction (PPI), and cleaving POI. In spite of large molecular size and the bottleneck of pharmacokinetic and physicochemical properties these technologies still have broad development prospect owing to high selectivity and wide adaptations.
Three-dimensional (3D) printing technology is a rapid prototyping technology for designing 3D models with special shape and complex internal structure via computer-aided/controlled drawing and preparing. This technology displays the characteristics of flexible processing, rapid shaping, low operating cost and high reliability. 3D printing technology may provide new strategies and approaches for the generation of a variety of new drug delivery systems, which makes its application in pharmaceutics attractive. This review briefly introduces the process and feature of 3D printing technology in preparation field and mainly introduces the research progress in the design and engineering of related preparations in the aspects of rate-controlled drug release, time-controlled drug release and targeted drug release. The prospects and challenges of 3D printing technology in the formulation engineering are analyzed.
Inflammatory bowel disease (IBD) is a chronic relapsing inflammatory disorder including mainly ulcerative colitis (UC) and Crohn's disease (CD). In China, IBD has become a common disease of the digestive system with an dramatic increase in incidence in recent years. The pathogenesis of IBD is not yet clear, and no drugs can completely cure IBD. Compared with monoclonal antibody drugs, small molecule drugs have the advantages of low cost, easy development as oral agents, and absence of immunogenicity. This review summarizes the recent research and development of small molecule immunosuppressants for IBD.
In this study, the effects of honokiol (HN) treatment for 24 h on lipid synthesis was examined in HepG2 cells. The parameters include intracellular lipid droplet and the expression of SREBP-1c and PNPLA3, glucose uptake, and oxidative stress including the expression of CYP2E1 and CYP4A in normal, TO901317 (TO)- and oleic acid (OA)-treated HepG2 cells. The lipid droplets were detected by oil red O staining. The glucose uptake was measured by fluorescence spectrophotometry using[2-(N-(7-nitrobenz-2-oxa-1, 3-diazol-4-yl) amino)-2-deoxyglucose, 2-NBDG] as probe. The expression levels of target genes were detected by quantitative PCR and Western blot. The results showed that:① TO (5 μmol·L-1) and OA (0.5 mmol·L-1) treatment increased the levels of intracellular lipid accumulation and the mRNA and protein expression of SREBP-1c and PNPLA3. After HN (10, 20, 40 μmol·L-1) treatment for 24 h, the lipid accumulation and the expression of SREBP-1c and PNPLA3 were all decreased in the tested cells. ② OA treatment significantly suppressed glucose uptake, while HN treatment dose-dependently increased the glucose uptake in OA-treated cells. ③ Compared with control group, CYP2E1 protein level significantly decreased in the three tested cells, and CYP4A protein level significantly decreased only in OA-treated cells following HN treatment. The above results suggest that HN may attenuate lipid accumulation by suppressing the expression of SREBP-1c and PNPLA3, and reduce lipid peroxidation and insulin resistance by down-regulation of the protein levels of CYP2E1 and CYP4A in HepG2 cells with steatosis.
Supersaturated drug delivery systems (SDDS) are defined as systems that are able to generate and maintain a sustained drug supersaturation in the gastrointestinal tract, facilitating the oral absorption of drugs with poor water solubility. Supersaturated drug solution is generated from a higher energy form of the drug or rapid dissolution through various formulation options. However, supersaturated solution is a thermodynamically unstable system that can easily lead to drug precipitation, missing the aim of improving the absorption. Therefore, maintenance of the supersaturated state is essential for the development of SDDS. Polymer-based SDDS take polymers as the precipitation inhibitor, which can effectively prevent the precipitation of drugs, generating an excellent effect on maintenance of the stability of supersaturated solution. However, different polymers have distinct anti-precipitation ability, and the mechanisms of such activity supported by the polymer remain unrevealed. In this review, we summarize the research advances in the absorption-enhancing mechanisms and in vitro evaluations of polymers-based SDDS. This review provides a reference for the design of rational SDDS.
IDO1 (indoleamine 2, 3-dioxygenase 1) is one of the most significant checkpoint in tumor immunology. Numerous studies indicates that IDO1 is abnormally expressed in breast cancer, colorectal cancer, liver cancer and other tumor tissues, participating in tumor immune escape through multiple pathways. This review is prepared to elucidate the biological function of IDO1, highlight its pivotal role in tumor evasion, and summarize IDO1 inhibitors in the clinical trials.
Present study was designed to investigate the effects and underlying antioxidant mechanism of klotho overexpression through an intracerebroventricular injection of a lentiviral vector that encoded murine klotho (LV-KL) on cerebral ischemia injury. Four weeks after the injection of lentivirus into the lateral ventricle of C57Balc/6J mice, a mouse model of global cerebral ischemia-reperfusion was established by bilateral common carotid artery occlusion (2VO). Klotho overexpression significantly improved neurobehavioral deficits and increased the number of survival neurons in the hippocampal CA1 and caudate putamen subregions. The overexpression also decreased malondialdehyde (MDA) content in brain, while mitochondrial manganese- superoxide dismutase (Mn-SOD) and catalase (CAT) expression in brain were increased. Moreover, klotho overexpression decreased Akt and forkhead box class O1 phosphorylation. These findings suggest that klotho may compensate for its aging-related decline to provide a promising therapeutic approach for the acute ischemic stroke during aging.
Flavonol glycoside is in clinical trials for treatment of hyperlipidemia. An accurate and sensitive liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated for the simultaneous determination of flavonol glycoside (M0), aglycone (M1) and glucuronide conjugate (M2) in rat plasma. d6-Flavonol glycoside was used as internal standard (IS). After extraction from the plasma by protein precipitation, the analytes and internal standard were separated on a XDB C18 column (50 mm×4.6 mm, 1.8 μm) using a gradient elution procedure. The mobile phase consisted of methanol and water (0.2% formic acid) at a flow rate of 0.6 mL·min-1. The total run time was 4.5 min. Positive electrospray ionization was performed using multiple reaction monitoring (MRM) with transitions of m/z 461.3 → m/z 299.1 for M0, m/z 299.1 → m/z 283.1 for M1, m/z 475.0 → m/z 299.1 for M2, and m/z 467.3 → m/z 305.1 for d6-flavonol glycoside. The method was validated and successfully applied to the pharmacokinetics study of flavonol glycoside in SD rats which were given flavonol glycoside (30 mg·kg-1) by gavage. The Cmax of M0 is (341 ±106) ng·mL-1 and AUC0-t is (1 960 ±725) h·ng·mL-1, while the Cmax of M2 is (1 720 ±843) ng·mL-1and AUC0-t is (8 510 ±2 920) h·ng·mL-1. The results suggest that flavonol glycoside existed mainly in the form of M0 and M2 in rats. After flavonol glycoside being hydrolyzed by the intestinal flora, it was absorbed in the form of aglycone and further metabolized to M2 after the first-pass effect. In this paper, the main metabolites of flavonol glycoside in rat plasma were determined for the first time, which provided a basis for the design of clinical pharmacokinetic experiment.