Latest ArticlesAccumulating evidence has shown that the cell-penetrating peptide TAT can be applied to deliver different types of drug molecules, including nucleic acids, proteins and small molecule drugs. Usually TAT delivers cargoes on the basis of their covalent bonds or non-covalent interactions. However, there are few reports on the delivery of proteins by TAT in a non-covalent manner, and no quantitative comparisons have been made on the protein delivery ability of TAT in fusion and non-fusion manners. In order to explore the ability of TAT to deliver proteins in non-fusion manner, here we used fluorescence microscopy and flow cytometry to investigate the ability of TAT to deliver enhanced green fluorescent protein (EGFP) into non-small cell lung cancer cells A549 in a non-fusion manner. It was found that TAT could deliver EGFP into A549 cells, and its delivery ability was positively correlated with its concentration. In addition, the fusion protein TAT-EGFP was overexpressed and purified, and its permeability across cell membrane was also investigated. In this paper, based on quantitative comparison, we found that the delivery of EGFP by TAT in fusion manner is significantly efficient than that of TAT in non-fusion manner. This is the report that TAT can deliver EGFP in a non-fusion manner. Although its delivery efficiency remains to be improved as compared with the fusion manner, the non-fusion manner has shown incomparable advantages in ease of operation, suggesting that it is also a candidate for delivery strategy in the future.
To investigate the crucial role of particle size in the biological effects of nanoparticles, a series of mesoporous silica nanoparticles (MSNs) were prepared with particle size gradients (50, 100, 150, 200 nm) with the traditional Stober method and adjusting the type and ratio of the silica source. The correlation between toxicity and size-caused biological effects were then further examined both in vitro and in vivo. The results indicated that the prepared MSNs had a uniform size, good dispersal, and ordered mesoporous structure. Hemolytic toxicity was found to be independent of particle size. At the cellular level, MSNs with smaller particle sizes were more readily internalized by cells, which initiated to more intense oxidative stress, therefor inducing higher cytotoxicity, and apoptosis rate. In vivo studies demonstrated that MSNs primarily accumulated in the liver and kidneys of mice. Pharmacokinetic analysis revealed that larger MSNs were eliminated more efficiently by the urinary system than smaller MSNs. The mice's body weight monitoring, blood tests, and pathological sections of major organs indicated good biocompatibility for MSNs of different sizes. Animal welfare and the animal experimental protocols were strictly consistent with related ethics regulations of Zhejiang Chinese Medical University. Overall, this study prepared MSNs with a particle size gradient to investigate the correlation between toxicity and particle size using macrophages and endothelial cells. The study also examined the biosafety of MSNs with different particle sizes in vivo and in vitro, which could help to improve the safety design strategy of MSNs for drug delivery systems.
There are many multi-original medicinal materials in Chinese Pharmacopoeia, and the mixed use of medicinal materials from different sources is common, which has certain influence on the stability of clinical medication. In this study, pyrosequencing technology was used to screen species-specific single nucleotide polymorphisms (SNP) from commonly used DNA barcode sequences, and a rapid and accurate molecular identification method for original species in mixed medicinal powder of Epimedii Folium was established. Multiple sequence alignment analysis showed that the 176th (C/T) mutation and the 196th (A/G) mutation of ITS, the 123rd (C/G) mutation of matK and the 892nd (A/C) mutation of rbcL could be used as the unique SNPs of E. sagittatum, E. koreanum, E. brevicornu and E. pubescens, respectively. In this study, the applicability of pyrosequencing and Sanger sequencing methods in the sequencing of mixture samples was investigated from the perspective of sensitivity and stability. Pyrosequencing method has higher detection sensitivity than Sanger sequencing method for low content samples in the mixed samples. Stability analysis showed that pyrosequencing technology could still obtain effective sequencing results for the amplified products of template DNA after 45 min of 95 ℃ high temperature water bath, while the critical point of Sanger sequencing method was 30 min. In this study, a new identification technology of Epimedii Folium mixed powder primordial species based on pyrosequencing and specific SNP was developed, which can quickly and accurately identify the mixed use of Epimedii Folium with high sensitivity and stability, and can also support the identification of different primordial species and mixed powder primordial herbs, which is conducive to ensuring the consistency and stability of clinical medication.
MYB transcription factors are involved in the regulation of various secondary metabolites biosynthesis. Gardenia jasminoides Ellis is the commonly used Chinese herbal medicine, and its main active ingredient is geniposide. Here, leaves and flower buds at different developmental stages of G. jasminoides were used to explore MYB transcription factors related to geniposide biosynthesis based on genome and transcriptome analysis. Transcriptome data analysis showed that, different from the expression of the common pathway genes for terpenoid biosynthesis, the expression level of genes in the specific pathway of geniposide biosynthesis was significantly higher in flower buds than in leaves, which was the same as the organ accumulation pattern of this component. And the promoter regions of geraniol synthase, iridoid synthase and geniposidic acid methyltransferase involved in the specific pathway all contained multiple MYB-binding sites. A total of 105 MYB transcription factors were obtained by annotating the coding genes of G. jasminoides, which were divided into 68 1R-MYB, 33 R2R3-MYB, 3 3R-MYB and 1 atypical MYB transcription factor according to the number of conserved domain. Based on the analysis of phylogenetic tree and quantitative real-time PCR, three candidate MYB transcription factors related to geniposide biosynthesis were selected, including potential positive regulation factor GjMYB23 and negative regulation factors GjMYB31 and GjMYB73. The results of this study will lay a foundation for searching the regulation of geniposide biosynthesis and further analysis of the quality formation mechanism of G. jasminoides, so as to promote the breeding of excellent varieties of G. jasminoides.
Most drugs need to interact with cell membrane to reach the biological target, so that membrane affinity assay is an important early screening step in drug discovery. However, at present, the traditional oil-water distribution method is still used, a new, simple and accurate method for membrane affinity assay is urgently needed. In this study, according to the colorimetric principle, a new assay model based on polydiacetylene vesicles was optimized through a series of experiments including different concentrations of vesicle solution, temperature, or pH reaction environment. On this basis, tetracaine hydrochloride, 2-methylimidazole and histamine were used as model drugs to measure the membrane affinity constants and verify the between-batch precision of the optimized assay model (relative standard deviation less than 5%). In addition, polydiacetylene vesicles were stable for up to 180 days, demonstrating the potential application of the assay model. This strategy is simple, stable, reliable, with high reproducibility, low cost and easy to promote, which provided a new tool and a new direction for the high-throughput assay of membrane affinity.
The global incidence rate of nonalcoholic steatohepatitis (NASH) continues to rise. The pathogenesis of NASH is complex, and there is no effective clinical treatment. Previous study has shown that DEAD box protein 5 (DDX5) can significantly alleviate the NASH process in mice. This study screened the natural product library of the research group and found that the active compound hypercalin B (HB) in Hypericum beanii N. Robson, a traditional Chinese medicine, can upregulate the expression of DDX5 protein in a dose-dependent manner. In this study, an in vitro model of NASH stimulated by palmitic acid (PA) and an animal model of NASH induced by the methionine- and choline-deficient diet (MCD) were constructed. Different concentrations of HB were used to investigate the effect and mechanism of HB in alleviating NASH progression. All animal experiments in this paper were approved by the Ethics Committee of China Pharmaceutical University (NO: 2021-02-003). In vitro model results showed that HB significantly reduced the intracellular lipid deposition induced by free fatty acid (FFA). Animal experiments showed that HB improved liver injury by significantly reducing lipid accumulation in the liver of NASH mice, and reducing serum aspartate transaminase (AST) and alanine transaminase (ALT) levels. Moreover, HB could inhibit liver inflammation by reducing the mRNA levels of liver pro-inflammatory cytokines including interleukin 6 (IL-6), interleukin 1β (IL-1β), and tumor necrosis factor α (TNFα). Further research showed that HB could reduce the phosphorylation level of the mechanical target of rapamycin (mTOR) and reduce the expression of sterol regulatory element binding protein 1 (SREBP1) and fatty acid synthase (FASN), thereby improving lipid metabolism and alleviating NASH progression, and the effects of HB against NASH were dependent on DDX5. In conclusion, HB can improve lipid metabolism and inhibit inflammatory activation by suppressing mTORC1 pathway via upregulating DDX5 protein, and showed promising anti-NASH activity in vitro and in vivo.
Although small molecule drugs (SMD) are still mainstream for the treatment of diseases, large molecule biologicss of many advantages, pose a challenge to the further discovery and use of SMD. The advantages of SMD are the convenience of oral administration and good patient compliance. However, the challenge with SMD is to integrate the PD, PK, selectivity and safety into a chemical structure. Because of their small size and surface area they often bind to various proteins, and off-target actions can cause adverse reactions. In this sense, selectivity is critical. Based upon target as the core to construct a chemical structure, it is necessary to consider the requirements of all the attributes, but achievement of the full-dimensional optimization is difficult. Modern drug discovery has been greatly enhanced by molecular biology and structural biology, and new strategies and technologies have emerged, which have created many successful medicines. For example, under the guidance of structural biology, covalent binding drugs connect moderate "electrophilic warheads" to the appropriate positions of molecules, and upon binding to their targets the electrophiles are irreversibly linked to the target by covalent bonds. Molecular biology can be directly applied to the development of antibody-coupled drugs (ADC). The antibody (A) acts as a carrier and a guide (for PK), and carries toxic molecules (D) into cancer cells, thus playing a killing role (for PD). The separate pharmacodynamic and pharmacokinetic entities are coupled (C) by linkers. PROTACs are also bifunctional molecules, which recruit a target protein and ubiquitin ligase E3 to form a ternary complex, which then acts as a catalyst to ubiquitinate the target protein and lead to degradation by the proteasome. In addition, in recent years, the combination of two fixed-dose drugs has improved selectivity, safety, and long-term benefit with many severe diseases, and can be regarded as an innovative strategy of physical combination. This review discusses some successful examples to briefly present the principles from the perspective of medicinal chemistry and therapeutic application.
Gouty arthritis is a type of metabolic rheumatic disease caused by autoimmune abnormalities. Currently, the use of Western medicine in the clinical treatment of gouty arthritis has been associated with a high risk of adverse reactions. Therefore, there is a growing interest in exploring therapeutic drugs from traditional Chinese medicine as a potential alternative. According to the theory of traditional Chinese medicine, gouty arthritis has been classified as damp-heat arthralgia syndrome. Shirebi granules has been found to have good clinical efficacy in treating gouty arthritis. However, its underlying pharmacological mechanisms remain unclear. To address this problem, the study first established the interaction network of candidate targets for Shirebi granules, which is used to treat damp-heat syndrome of gouty arthritis. Then, the key candidate targets of Shirebi granules for treating gouty arthritis with damp-heat syndrome were screened by calculating the topological features of the network nodes. Then, the functional mining of the key candidate targets revealed that the candidate targets of Shirebi granules may intervene in the biological process of inflammatory response and lipid metabolism through the crosstalk of Wnt/β-catenin signaling. To verify the effectiveness of Shirebi granules in treating gouty arthritis with damp-heat syndrome, a rat model was established. The results demonstrated that the granules significantly improved the severity of arthritis in rats with this condition, reduced joint inflammation, gait score, swelling index, increased mechanical pain threshold (P < 0.05), and reduced the content of serum inflammatory factors IL-1β, IL-6, and TNF-α in gouty arthritis rats with damp-heat syndrome (P < 0.01) gouty. It was also found that Shirebi granules effectively alleviated the symptoms of dampness heat syndrome such as local joint fever and dry mouth by reducing the temperature of the joints in acute gouty arthritis with damp-heat syndrome (AD) rats, increasing the threshold of heat pain, increasing water intake (P < 0.01), and inhibiting abnormal changes in the content of fatty acid oxidation related enzymes (P < 0.01). Western blot analysis showed that Shirebi granules increased the protein expression levels of Wnt and β-catenin (P < 0.01) while decreasing the protein expression of p65, p-p65 and PPARγ (P < 0.01) in rats with gouty arthritis and damp-heat syndrome. The results showed that Shirebi granules may reverse the "inflammation-immune" imbalance and lipid metabolism disorder by regulating the crosstalk of Wnt/β-catenin signaling, and play a role in alleviating the severity of the disease. This study provides a methodological reference for elucidating the pharmacological mechanisms of traditional Chinese medicine formulas. It also presents research ideas for the appropriate clinical use of Chinese patent medicines and the development of new clinical drugs for gouty arthritis therapy. The animal welfare and experiment procedures of this study were performed in accordance with the regulations of the Experimental Animal Ethics Committee of Experimental Research Center, China Academy of Chinese Medical Sciences (grant No. ERCCACMS11-2302-08).
Toll like receptors (TLRs) are the earliest discovered natural immune pattern recognition receptors (PRRs). The abnormality of TLR signal transduction pathway is the key factor leading to chronic inflammatory, cancer, nervous system disease and cardiovascular diseases. The development of TLR agonists and inhibitors has attracted much attention. Currently known TLR2 agonists, such as lipopeptides or their derivatives, have certain limitations in drug development due to their difficult synthesis, easy hydrolysis, and triggering inflammatory cytokine storms, while inhibitors have been rarely reported. New small molecule TLR2 agonists or inhibitors with higher stability are more likely to be developed as tumor immunotherapy or anti-inflammatory drugs.
Statins are a class of hydroxymethylglutaryl-CoA reductase inhibitors (HMG-CoA reductase inhibitors), which are widely used to reduce blood lipid in clinic, and are especially important for the prevention and treatment of cardiovascular diseases. In recent years, many studies at home and abroad believe that statins have a unique role in tumor prevention and treatment, and have been widely concerned. In terms of epigenetic regulation mechanism, statins mainly affect the progress of tumor through DNA methylation, histone modification and miRNA regulation. In addition, statins can also achieve their anti-tumor effects by promoting tumor cell autophagy, regulating tumor cell cycle, and promoting tumor cell apoptosis and other signaling pathways. Therefore, the research on statins provides ideas for the discovery of new anti-tumor treatments. In this paper, the role of statins in the prevention and treatment of common tumors is reviewed, including its mechanism of inhibiting the occurrence and development of tumors through epigenetic regulation and other related mechanisms, as well as its clinical research status.