RESUMO
Pien Tze Huang (PZH), a common hepatoprotective Traditional Chinese Medicine that has been found to be an effective treatment for carbon tetrachlorideinduced hepatic damage, including liver fibrosis. Circular RNAs (circRNAs) serve a crucial role in regulating gene expression levels via circRNA/micro (mi)RNA/mRNA networks in several human diseases and biological processes. However, whether circRNAs are involved in the underlying mechanism of the therapeutic effects of PZH on liver fibrosis remains unclear. Therefore, the aim of the present study was to investigate these effects using circRNA expression profiles from PZHtreated fibrotic livers in model mice. A casecontrol study on >59,476 circRNAs from CCl4induced (control group, n=6) and PZHtreated (case group, n=6) mice was performed using circRNA sequencing in liver tissues. PZH treatment resulted in the differential expression of 91 circRNAs, including 58 upregulated and 33 downregulated circRNAs. Furthermore, the construction of competing endogenous networks also indicated that differentially expressed circRNAs acted as miRNA sponges. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis of miRNA targets demonstrated that PZHaffected circRNAs were mainly involved in biological processes such as 'positive regulation of fibroblast proliferation', 'cellular response to interleukin1' and 'regulation of DNAtemplated transcription in response to stress' and in a number of important pathways, such as 'TNF signaling pathway', 'PI3KAkt signaling pathway', 'IL17 signaling pathway' and 'MAPK signaling pathway'. To further validate the bioinformatics data, reverse transcription-quantitative PCR was performed on seven miRNA targets in a human hepatic stellate LX2 cell model. The results suggested that seven of the miRNAs exhibited regulatory patterns that were consistent with those of the transcriptome sequencing results. KaplanMeier survival analysis demonstrated that the expression levels of dihydrodiol dehydrogenase and solute carrier family 7, member 11 gene were significantly associated with patient survival, 269 patients with liver hepatocellular carcinoma from The Cancer Genome Atlas database. To the best of our knowledge, this was the first study to provide evidence that PZH affects circRNA expression levels, which may serve important roles in PZHtreated fibrotic liver through the regulation of functional gene expression. In conclusion, the present study provided new insights into the mechanism underlying the pathogenesis of liver fibrosis and identified potential novel, efficient, therapeutic targets against liver injury.
Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , MicroRNAs , Animais , Biomarcadores/metabolismo , Tetracloreto de Carbono/farmacologia , Carcinoma Hepatocelular/genética , Estudos de Casos e Controles , Medicamentos de Ervas Chinesas , Perfilação da Expressão Gênica/métodos , Redes Reguladoras de Genes , Humanos , Cirrose Hepática/tratamento farmacológico , Cirrose Hepática/genética , Cirrose Hepática/patologia , Neoplasias Hepáticas/genética , Camundongos , MicroRNAs/genética , MicroRNAs/metabolismo , Fosfatidilinositol 3-Quinases/genética , RNA/genética , RNA Circular/genéticaRESUMO
The powerful insecticidal and multi-drug-resistance-reversing activities displayed by the stemofoline group of alkaloids render them promising lead structures for further development as commercial agents in agriculture and medicine. However, concise, enantioselective total syntheses of stemofoline alkaloids remain a formidable challenge due to their structural complexity. We disclose herein the enantioselective total syntheses of four stemofoline alkaloids, including (+)-stemofoline, (+)-isostemofoline, (+)-stemoburkilline, and (+)-(11S,12R)-dihydrostemofoline, in just 19 steps. Our strategy relies on a biogenetic hypothesis, which postulates that stemoburkilline and dihydrostemofolines are biogenetic precursors of stemofoline and isostemofoline. Other highlights of our approach are the use of Horner-Wadsworth-Emmons reaction to connect the two segments of the molecule, an improved protocol allowing gram-scale access to the tetracyclic cage-type core, and a Cu-catalyzed direct and versatile nucleophilic alkylation reaction on an anti-Bredt iminium ion. The synthetic techniques that we developed could also be extended to the preparation of other Stemona alkaloids.