The use of melittin to enhance transgene expression mediated by recombinant adeno-associated virus serotype 2 vectors both in vitro and in vivo / 中西医结合学报

OBJECTIVE@#Melittin, a cell-penetrating peptide, improves the efficiency of many non-viral gene delivery vectors, yet its application in viral vectors has not been well studied. The non-pathogenic recombinant adeno-associated virus (rAAV) vector is an ideal in vivo gene delivery vector. However, its full potential will only be achieved after improvement of its transduction efficiency. To improve the transduction efficiency of rAAV2 vectors, we attempted to develop a melittin-based rAAV2 vector delivery strategy.@*METHODS@#The melittin peptide was inserted into the rAAV2 capsid either in the loop VIII of all viral proteins (VPs) or at the N terminus of VP2. Various rAAV2-gfp or -fluc vectors were subjected to quantitative real-time polymerase chain reaction and Western blot assays to determine their titers and integrity of capsid proteins, respectively. Alternatively, the vectors based on wild-type capsid were pre-incubated with melittin, followed by transduction of cultured cells or tail vein administration of the mixture to C57BL/6 and BALB/c nude mice. In vivo bioluminescence imaging was performed to evaluate the transgene expression.@*RESULTS@#rAAV2 vectors with melittin peptide inserted in the loop VIII of VPs had low transduction efficiency, probably due to dramatically reduced ability to bind to the target cells. Fusing the melittin peptide at the N-terminus of VP2 produced vectors without the VP2 subunit. Interestingly, among the commonly used rAAV vectors, pre-incubation of rAAV2 and rAAV6 vectors with melittin significantly enhanced their transduction efficiency in HEK293 and Huh7 cells in vitro. Melittin also had the ability to increase the rAAV2-mediated transgene expression in mouse liver in vivo. Mechanistically, melittin did not change the vector-receptor interaction. Moreover, cell counting kit-8 assays of cultured cells and serum transaminase levels indicated melittin had little cytotoxicity.@*CONCLUSION@#Pre-incubation with melittin, but not insertion of melittin into the rAAV2 capsid, significantly enhanced rAAV2-mediated transgene expression. Although further in vivo evaluations are required, this research not only expands the pharmacological potential of melittin, but also provides a new strategy to improve gene therapy mediated by rAAV vectors.

Compatibility Rules of Prescriptions Containing Forsythiae Fructus in Dictionary of Traditional Chinese Medicine Prescriptions and Anti-inflammatory Mechanism： An Exploration Based on Data Mining and Network Pharmacology / 中国实验方剂学杂志

Objective:To analyze the compatibility rules of prescriptions containing Forsythiae Fructus based on data mining and explore the anti-inflammatory mechanism of Forsythiae Fructus based on network pharmacology，so as to provide reference for the rational clinical application of Forsythiae Fructus and the development of health foods and new Chinese medicines. Method:The prescriptions containing Forsythiae Fructus in the<italic> Dictionary of Traditional Chinese Medicine Prescriptions</italic> were collected，based on which a clinical prescription database was constructed. The Chinese herbs combined with Forsythiae Fructus and the corresponding indications were subjected to frequency statistics，association rule analysis，and complex network analysis using SPSS Statistics 26，IBM SPSS Modeler 18.0，and Gephi 9.2. The active components and targets of Forsythiae Fructus for anti-inflammation were retrieved from the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform （TCMSP），BATMAN-TCM，and SEA，and the targets related to anti-inflammation from GeneCards，Online Mendelian Inheritance in Man （OMIM），CTD，and GenCLiP3. Following the analysis of protein-protein interactions （PPI） with STRING，a PPI network was constructed. The enrichment analysis was performed using Metascape，and the active component-anti-inflammation target-signaling pathway network of Forsythiae Fructus was constructed by Cytoscape 3.8.2. Result:According to the inclusion and exclusion criteria，2 245 prescriptions containing Forsythiae Fructus were harvested，involving 512 Chinese herbs，with a total usage frequency of 27 314. The Chinese herbs that were most frequently combined with Forsythiae Fructus （>800 times） were Glycyrrhizae Radix et Rhizoma （1 483 times），Scutellariae Radix （964 times），and Angelicae Sinensis Radix （842 times）. Hence，the herbal pairs "Forsythiae Fructus-Scutellariae Radix" and "Forsythiae Fructus-Angelicae Sinensis Radix" were further explored. The prescriptions containing Forsythiae Fructus could be utilized for the treatment of 29 kinds of diseases，and three representative disease categories including "carbuncle，gangrene，sores and ulcers"，"ophthalmic diseases and syndromes" and "epidemic diseases" are selected for data mining. There were 19 association rules obtained with "Forsythiae Fructus-Glycyrrhizae Radix et Rhizoma-Lonicerae Japonicae Flos-Angelicae Sinensis Radix" as the core herb combination for "carbuncle，gangrene，sores and ulcers". The clustering analysis revealed one multi-herb clustering group，four herbal pairs，and single herb Lonicerae Japonicae Flos，the complex network analysis four herbal modules，and the factor analysis six common factors. There were 23 association rules obtained with "Forsythiae Fructus-Glycyrrhizae Radix et Rhizoma-Scutellariae Radix-Angelicae Sinensis Radix" as the core herb combination for "ophthalmic diseases and syndromes". The clustering analysis revealed two multi-herb clustering groups and four herbal pairs，the complex network analysis four herbal modules，and the factor analysis five common factors. There were 28 association rules obtained with "Forsythiae Fructus-Glycyrrhizae Radix et Rhizoma-Menthae Haplocalycis Herba-Lonicerae Japonicae Flos" as the core herb combination for "epidemic diseases". The clustering analysis revealed three multi-herb clustering groups，one herbal pair，and two single herbs Forsythiae Fructus and Glycyrrhizae Radix et Rhizoma，the complex network analysis four herbal modules，and the factor analysis five common factors. As demonstrated by network pharmacology-based analysis，the core anti-inflammation components of Forsythiae Fructus were quercetin，luteolin，and kaempferol，and the core targets were phosphoinositide-3-kinase regulatory subunit 1 （PIK3R1），protein kinase B 1 （Akt1），and epidermal growth factor receptor（EGFR）. The biological pathways were mainly concentrated in proteoglycans in cancer，pathways in cancer，and PI3K/Akt signaling pathway，with such functions as inhibition of transcription factors，regulation of enzyme activity，and inflammation-related gene expression involved. Conclusion:This study employed a variety of data mining techniques to objectively，intuitively，and scientifically uncover the compatibility rules of Forsythiae Fructus in the treatment of high-frequency diseases. It has been found that Forsythiae Fructus is often combined with heat-clearing herbs，tonifying herbs，exterior-releasing herbs，and blood-activating and stasis-resolving herbs for diverse diseases and syndromes. Under the premise of clearing heat and removing toxin，reinforcing healthy Qi and dredging stagnation are also emphasized. According to the degree of internal heat exuberance，the heat-clearing herbs with different merits are combined. This study has revealed the unique advantages of Forsythiae Fructus in the treatment of specific diseases and syndromes as well as its multi-component，multi-target，and multi-pathway mechanisms in anti-inflammation，breaking through the limitations in modern clinical and experimental research of Forsythiae Fructus. These findings are of great significance for guiding the rational clinical application of Forsythiae Fructus and the development of health foods and new Chinese medicines，thus better accelerating the development of Chinese medicine health industry.

The use of miR122 and its target sequence in adeno-associated virus-mediated trichosanthin gene therapy / 中西医结合学报

OBJECTIVE@#Plant-derived cytotoxic transgene expression, such as trichosanthin (tcs), regulated by recombinant adeno-associated virus (rAAV) vector is a promising cancer gene therapy. However, the cytotoxic transgene can hamper the vector production in the rAAV producer cell line, human embryonic kidney (HEK293) cells. Here, we explored microRNA-122 (miR122) and its target sequence to limit the expression of the cytotoxic gene in the rAAV producer cells.@*METHODS@#A miR122 target (122T) sequence was incorporated into the 3' untranslated region of the tcs cDNA sequence. The firefly luciferase (fluc) transgene was used as an appropriate control. Cell line HEK293-mir122 was generated by the lentiviral vector-mediated genome integration of the mir122 gene in parental HEK293 cells. The effects of miR122 overexpression on cell growth, transgene expression, and rAAV production were determined.@*RESULTS@#The presence of 122T sequence significantly reduced transgene expression in the miR122-enriched Huh7 cell line (in vitro), fresh human hepatocytes (ex vivo), and mouse liver (in vivo). Also, the normal liver physiology was unaffected by delivery of 122T sequence by rAAV vectors. Compared with the parental cells, the miR122-overexpressing HEK293-mir122 cell line showed similar cell growth rate and expression of transgene without 122T, as well as the ability to produce liver-targeting rAAV vectors. Fascinatingly, the yield of rAAV vectors carrying the tcs-122T gene was increased by 77.7-fold in HEK293-mir122 cells. Moreover, the tcs-122T-containing rAAV vectors significantly reduced the proliferation of hepatocellular carcinoma cells without affecting the normal liver cells.@*CONCLUSION@#HEK293-mir122 cells along with the 122T sequence provide a potential tool to attenuate the cytotoxic transgene expression, such as tcs, during rAAV vector production.