RESUMO
Lethal small molecules are useful probes to discover and characterize novel cell death pathways and biochemical mechanisms. Here we report that the synthetic oxime-containing small molecule caspase-independent lethal 56 (CIL56) induces an unconventional form of nonapoptotic cell death distinct from necroptosis, ferroptosis, and other pathways. CIL56-induced cell death requires a catalytically active protein S-acyltransferase complex comprising the enzyme ZDHHC5 and an accessory subunit GOLGA7. The ZDHHC5-GOLGA7 complex is mutually stabilizing and localizes to the plasma membrane. CIL56 inhibits anterograde protein transport from the Golgi apparatus, which may be lethal in the context of ongoing ZDHHC5-GOLGA7 complex-dependent retrograde protein trafficking from the plasma membrane to internal sites. Other oxime-containing small molecules, structurally distinct from CIL56, may trigger cell death through the same pathway. These results define an unconventional form of nonapoptotic cell death regulated by protein S-acylation.
Assuntos
Aciltransferases/metabolismo , Morte Celular , Proteínas da Matriz do Complexo de Golgi/metabolismo , Acilação , Aciltransferases/química , Aciltransferases/genética , Animais , Morte Celular/efeitos dos fármacos , Linhagem Celular , Membrana Celular/metabolismo , Compostos de Anéis Fundidos/química , Compostos de Anéis Fundidos/farmacologia , Complexo de Golgi/efeitos dos fármacos , Complexo de Golgi/metabolismo , Complexo de Golgi/ultraestrutura , Proteínas da Matriz do Complexo de Golgi/química , Proteínas da Matriz do Complexo de Golgi/genética , Humanos , Camundongos , Oximas/química , Oximas/farmacologia , Proteína S/metabolismo , Transporte Proteico/efeitos dos fármacosRESUMO
Cissampelos sympodialis Eichler is well studied and investigated for its antiasthmatic properties, but there are no data in the literature describing antibacterial properties of alkaloids isolated from this botanical species. This work reports the isolation and characterization of phanostenine obtained from roots of C. sympodialis and describes for the first time its antimicrobial and antibiotic modulatory properties. Phanostenine was first isolated from Cissampelos sympodialis and its antibacterial activities were determined. Chemical structures of the alkaloid isolate were determined using spectroscopic and chemical analyses. Phanostenine was also tested for its antibacterial activity against standard strains and clinical isolates of Escherichia coli and Staphylococcus aureus. Minimal inhibitory concentration (MIC) was determined in a microdilution assay and for the evaluation of antibiotic resistance-modifying activity. MIC of the antibiotics was determined in the presence or absence of phanostenine at sub-inhibitory concentrations. The evaluation of antibacterial activity by microdilution assay showed activity for all strains with better values against S. aureus ATCC 12692 and E. coli 27 (787.69â mm). The evaluation of aminoglycoside antibiotic resistance-modifying activity showed reduction in the MIC of the aminoglycosides (amikacin, gentamicin and neomycin) when associated with phanostenine, MIC reduction of antibiotics ranging from 21 % to 80 %. The data demonstrated that phanostenine possesses a relevant ability to modify the antibiotic activity inâ vitro. We can suggest that phanostenine presents itself as a promising tool as an adjuvant for novel antibiotics formulations against bacterial resistance.
Assuntos
Alcaloides/química , Antibacterianos/química , Derivados de Benzeno/química , Cissampelos/química , Compostos Heterocíclicos de 4 ou mais Anéis/química , Alcaloides/isolamento & purificação , Alcaloides/farmacologia , Antibacterianos/isolamento & purificação , Antibacterianos/farmacologia , Derivados de Benzeno/isolamento & purificação , Derivados de Benzeno/farmacologia , Cissampelos/metabolismo , Farmacorresistência Bacteriana/efeitos dos fármacos , Compostos de Anéis Fundidos , Compostos Heterocíclicos de 4 ou mais Anéis/isolamento & purificação , Compostos Heterocíclicos de 4 ou mais Anéis/farmacologia , Testes de Sensibilidade Microbiana , Extratos Vegetais/química , Raízes de Plantas/química , Raízes de Plantas/metabolismo , Staphylococcus aureus/efeitos dos fármacosRESUMO
BACKGROUND: Euphorbia factor L2 has potent effects on ascites, hydropsy and cancers. PURPOSE: We investigated the pharmacological effects of Euphorbia factor L2 (EFL2) on hepatocellular carcinoma (HCC). METHODS: MTT assay was conducted to determine the proliferative activity of EFL2 on Hep G2 and SMMC-7721 cells. Wound-healing assay, colony formation assay, western blotting and quantitative PCR were carried out to examine the cell migration, p-AKT and p-STAT3 signaling. Moreover, we used human tumor xenograft BALB/c nude mice to detect the effect of EFL2 on HCC in vivo. RESULTS: EFL2 inhibited the proliferation of SMMC-7721 and Hep G2 cells in concentration- and time-dependent manners. EFL2 also suppressed the cell migration and colony formation of hepatocellular carcinoma cells. Using a transforming growth factor-ß (TGF-ß)-induced epithelial-mesenchymal transition (EMT) model, we provided evidences that EFL2 could also inhibit TGF-ß induced cell growth, vimentin, N-cadherin expressions, activation of p-AKT and p-STAT3, whereas up-regulate E-cadherin expression. Furthermore, EFL2 inhibited tumor growth and STAT3 phosphorylation in vivo. CONCLUSION: In conclusion, EFL2 has the potential to be explored as a candidate treatment agent for HCC by inhibiting cell growth and migration both in vitro and in vivo.