Isoliquiritigenin induces HMOX1 and GPX4-mediated ferroptosis in gallbladder cancer cells / 中华医学杂志(英文版)

BACKGROUND@#Gallbladder cancer (GBC) is the most common malignant tumor of biliary tract. Isoliquiritigenin (ISL) is a natural compound with chalcone structure extracted from the roots of licorice and other plants. Relevant studies have shown that ISL has a strong anti-tumor ability in various types of tumors. However, the research of ISL against GBC has not been reported, which needs to be further investigated.@*METHODS@#The effects of ISL against GBC cells in vitro and in vivo were characterized by cytotoxicity test, RNA-sequencing, quantitative real-time polymerase chain reaction, reactive oxygen species (ROS) detection, lipid peroxidation detection, ferrous ion detection, glutathione disulphide/glutathione (GSSG/GSH) detection, lentivirus transfection, nude mice tumorigenesis experiment and immunohistochemistry.@*RESULTS@#ISL significantly inhibited the proliferation of GBC cells in vitro . The results of transcriptome sequencing and bioinformatics analysis showed that ferroptosis was the main pathway of ISL inhibiting the proliferation of GBC, and HMOX1 and GPX4 were the key molecules of ISL-induced ferroptosis. Knockdown of HMOX1 or overexpression of GPX4 can reduce the sensitivity of GBC cells to ISL-induced ferroptosis and significantly restore the viability of GBC cells. Moreover, ISL significantly reversed the iron content, ROS level, lipid peroxidation level and GSSG/GSH ratio of GBC cells. Finally, ISL significantly inhibited the growth of GBC in vivo and regulated the ferroptosis of GBC by mediating HMOX1 and GPX4 .@*CONCLUSION@#ISL induced ferroptosis in GBC mainly by activating p62-Keap1-Nrf2-HMOX1 signaling pathway and down-regulating GPX4 in vitro and in vivo . This evidence may provide a new direction for the treatment of GBC.

Carbon monoxide releasing molecule-2 suppresses stretchactivated atrial natriuretic peptide secretion by activating largeconductance calcium-activated potassium channels

Carbon monoxide (CO) is a known gaseous bioactive substance found across a wide array of body systems. The administration of low concentrations of CO has been found to exert an anti-inflammatory, anti-apoptotic, anti-hypertensive, and vaso-dilatory effect. To date, however, it has remained unknown whether CO influences atrial natriuretic peptide (ANP) secretion. This study explores the effect of CO on ANP secretion and its associated signaling pathway using isolated beating rat atria. Atrial perfusate was collected for 10 min for use as a control, after which high atrial stretch was induced by increasing the height of the outflow catheter. Carbon monoxide releasing molecule-2 (CORM-2; 10, 50, 100 µM) and hemin (HO-1 inducer; 0.1, 1, 50 µM), but not CORM-3 (10, 50, 100 µM), decreased high stretch-induced ANP secretion. However, zinc porphyrin (HO-1 inhibitor) did not affect ANP secretion. The order of potency for the suppression of ANP secretion was found to be hemin > CORM-2 >> CORM-3. The suppression of ANP secretion by CORM-2 was attenuated by pretreatment with 5-hydroxydecanoic acid, paxilline, and 1H-[1,2,4] oxadiazolo [4,3-a] quinoxalin-1-one, but not by diltiazem, wortmannin, LY-294002, or NG-nitroL-arginine methyl ester. Hypoxic conditions attenuated the suppressive effect of CORM-2 on ANP secretion. In sum, these results suggest that CORM-2 suppresses ANP secretion via mitochondrial K ATP channels and large conductance Ca 2+ -activated K+ channels.

Regulation of dry substance and active components accumulation in fruit of Forsythia suspensa / 中草药

Objective To study the regulation of dry substance and active components accumulation in the fruit of Forsythia suspensa. Methods The dry substance of the fruit was analyzed by the method of hundred grain mass. The contents of the active components in leaves, shucks, and seeds were analyzed by HPLC. Results The period for F. suspensa to accumulate the dry substance was mainly May and July. During the whole growth phase, the active components, such as forsythiaside, forsythin, and rutin in different parts, were decreasing. From the last ten-day of August to the first ten-day of September, the accumulation of the dry substance came to stability and the contents of active components in shucks and seed were stable. The contents of active components in shucks decreased rapidly from September to October, and then came to stability and the contents in shucks is the least during the last ten-day of October. So the contents of active components in younger F. suspensa are higher than that in elder one, and the proportion among forsythiaside, forsythins, and lution is also significantly different from elder seeds. Conclusion It is more preferable to pick younger F. suspensa from the last ten-day of August to the first ten-day of September and to pick elder F. suspensa during last ten-day of October.