Lipid nanoparticle delivery of siRNA targeting Cyp2e1 gene attenuates subacute alcoholic liver injury in mice / 浙江大学学报·医学版

OBJECTIVES@#To investigate the effect and mechanism of lipid nanoparticle (LNP) delivery of small interfering RNA (siRNA) targeting Cyp2e1 gene on subacute alcoholic liver injury in mice.@*METHODS@#siRNA targeting Cyp2e1 gene was encapsulated in LNP (si-Cyp2e1 LNP) by microfluidic technique and the resulting LNPs were characterized. The optimal dose of si-Cyp2e1 LNP administration was screened. Forty female C57BL/6N mice were randomly divided into blank control group, model control group, si-Cyp2e1 LNP group, LNP control group and metadoxine group. The subacute alcoholic liver injury mouse model was induced by ethanol feeding for 10 d plus ethanol gavage for the last 3 d. Serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST) activities, and the superoxide dismutase (SOD) activity as well as malondialdehyde, reactive oxygen species, glutathione, triacylglycerol, total cholesterol contents in liver tissue were measured in each group, and liver index was calculated. The expression of genes related to oxidative stress, lipid synthesis and inflammation in each group of mice were measured by realtime RT-PCR.@*RESULTS@#Compared with the model control group, the levels of liver index, serum ALT, AST activities, malondialdehyde, reactive oxygen species, triacylglycerol, total cholesterol contents in liver tissue decreased, but the SOD activity as well as glutathione increased in the si-Cyp2e1 LNP group (all P<0.01). Hematoxylin-eosin staining result showed disorganized hepatocytes with sparse cytoplasm and a large number of fat vacuoles and necrosis in the model control group, while the si-Cyp2e1 LNP group had uniformly sized and arranged hepatocytes with normal liver tissue morphology and structure. Oil red O staining result showed si-Cyp2e1 LNP group had lower fat content of the liver compared to the model control group (P<0.01), and no fat droplets accumulated. Anti-F4/80 monoclonal antibody fluorescence immunohistochemistry showed that the si-Cyp2e1 LNP group had lower cumulative optical density values compared to the model control group (P<0.01) and no significant inflammatory reaction. Compared with the model control group, the expression of catalytic genes P47phox, P67phox and Gp91phox were reduced (all P<0.01), while the expression of the antioxidant enzyme genes Sod1, Gsh-rd and Gsh-px were increased (all P<0.01). The mRNA expression of the lipid metabolism genes Pgc-1α and Cpt1 were increased (all P<0.01) and the lipid synthesis-related genes Srebp1c, Acc and Fasn were decreased (all P<0.01); the expression of liver inflammation-related genes Tgf-β, Tnf-α and Il-6 were decreased (all P<0.01).@*CONCLUSIONS@#The si-Cyp2e1 LNP may attenuate subacute alcoholic liver injury in mice mainly by reducing reactive oxygen levels, increasing antioxidant activity, blocking oxidative stress pathways and reducing ethanol-induced steatosis and inflammation.

Natural exosome-like nanovesicles from edible tea flowers suppress metastatic breast cancer via ROS generation and microbiota modulation

Although several artificial nanotherapeutics have been approved for practical treatment of metastatic breast cancer, their inefficient therapeutic outcomes, serious adverse effects, and high cost of mass production remain crucial challenges. Herein, we developed an alternative strategy to specifically trigger apoptosis of breast tumors and inhibit their lung metastasis by using natural nanovehicles from tea flowers (TFENs). These nanovehicles had desirable particle sizes (131 nm), exosome-like morphology, and negative zeta potentials. Furthermore, TFENs were found to contain large amounts of polyphenols, flavonoids, functional proteins, and lipids. Cell experiments revealed that TFENs showed strong cytotoxicities against cancer cells due to the stimulation of reactive oxygen species (ROS) amplification. The increased intracellular ROS amounts could not only trigger mitochondrial damage, but also arrest cell cycle, resulting in the in vitro anti-proliferation, anti-migration, and anti-invasion activities against breast cancer cells. Further mice investigations demonstrated that TFENs after intravenous (i.v.) injection or oral administration could accumulate in breast tumors and lung metastatic sites, inhibit the growth and metastasis of breast cancer, and modulate gut microbiota. This study brings new insights to the green production of natural exosome-like nanoplatform for the inhibition of breast cancer and its lung metastasis via i.v. and oral routes.