Shell engineering in soft alginate-based capsules for culturing liver spheroids.

Functional interaction between cancer cells and the surrounding microenvironment is still not sufficiently understood, which motivates the tremendous interest for the development of numerous in vitro tumor models. Diverse parameters, for example, transport of nutrients and metabolites, availability of space in the confinement, etc. make an impact on the size, shape, and metabolism of the tumoroids. We demonstrate the fluidics-based low-cost methodology to reproducibly generate the alginate and alginate-chitosan microcapsules and apply it to grow human hepatoma (HepG2) spheroids of different dimensions and geometries. Focusing specifically on the composition and thickness of the hydrogel shell, permeability of the microcapsules was selectively tuned. The diffusion of the selected benchmark molecules through the shell has been systematically investigated using both, experiments and simulations, which is essential to ensure efficient mass transfer and/or filtering of the biochemical species. Metabolic activity of spheroids in microcapsules was confirmed by tracking the turnover of testosterone to androstenedione with chromatography studies in a metabolic assay. Depending on available space, phenotypically different 3D cell assemblies have been observed inside the capsules, varying in the tightness of cell aggregations and their shapes. Conclusively, we believe that our system with the facile tuning of the shell thickness and permeability, represents a promising platform for studying the formation of cancer spheroids and their functional interaction with the surrounding microenvironment.

Possible Glutathione Peroxidase 4-Independent Reduction of Phosphatidylcholine Hydroperoxide: Its Relevance to Ferroptosis.

Ferroptosis is mainly caused by iron-mediated peroxidation of phospholipids and has recently attracted attention due to its involvement in various diseases. At the center of it is supposedly the inability of glutathione peroxidase 4 (GPX4) to reduce excess peroxidized phospholipids (e.g., phosphatidylcholine hydroperoxide (PCOOH)) that trigger ferroptosis. However, the involvement of enzymes other than GPX4 in ferroptosis is scarcely known. To elucidate this matter, we evaluated the uptake of PCOOH in a GPX4 knockout (KO) human hepatoma cell line HepG2 generated using CRISPR-Cas9. After confirming that GPX4 expression in the KO cells was below the detection limit, we cultured both wild-type (WT) and GPX4 KO HepG2 cells in a medium containing 50 µM PCOOH for 1-8 hours. By analyzing the level of PCOOH and its reduction product (phosphatidylcholine hydroxide, PCOH) in cells using liquid chromatography-tandem mass spectrometry, we detected the cellular uptake of PCOOH. On top of this, we detected a large amount of PCOH not only in WT HepG2 but also in GPX4 KO HepG2, thus indicating the notable involvement of enzymes other than GPX4 (e.g., other GPX family, glutathione S-transferase, thioredoxin, or peroxiredoxin) in reducing PCOOH. Further corroboration of these findings hopefully leads to the development of novel methods to prevent ferroptosis-related diseases by targeting enzymes other than GPX4.

In Vitro and In Vivo Protective Effects of Flavonoid-Enriched Lotus Seedpod Extract on Lipopolysaccharide-Induced Hepatic Inflammation.

Endotoxin lipopolysaccharide (LPS) plays an important role in the acceleration of hepatic inflammation. Natural medicinal plants that can prevent inflammation by targeting LPS have potential therapeutic clinical application. The aim of the study is to examine the anti-inflammatory effects of lotus seedpod extract (LSE), used as a traditional Chinese herbal medicine with hemostasis function and for eliminating bruise, on the LPS-induced hepatic inflammation and its underlying molecular mechanisms in vitro and in vivo. In vitro, LSE and its purified compound (-)-epigallocatechin (EGC) dose-dependently inhibited the expressions of pro-inflammatory cytokines and mediators, including tumor necrosis factor (TNF)- α , interleukin (IL)-6, cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS), without affecting cell viability in LPS-stimulated human hepatoma cell line HepG2. Molecular studies showed the anti-LPS effect of HLP or EGC might be mediated via downregulation of Toll-like receptor 4. (TLR4)-mediated both NF- κ B and p38 signaling, as demonstrated by the usage of pyrrolidine dithiocarbamate (PDTC), a specific NF- κ B inhibitor. In vivo, LPS-induced hepatic inflammation was significantly ameliorated in LSE-fed mice as gauged by dose-dependent inhibition of serum levels of biochemical markers of liver damage, the changes of hepatic lobular architecture and the secretion of pro-inflammatory mediators, as well as induction of anti-oxidant enzymes. As a result, our data presented the first evidence of EGC-enriched LSE as an anti-inflammatory agent in LPS-stimulated HepG2 cells and mice, and these findings may open interesting perspectives to the strategy in treatment for hepatic inflammation.

Study on Synthesis and Anti-tumor Activity of 6 Kinds of Tectorigenin Mannich Base Derivatives / 中国药房

OBJECTIVE： To conduct structural modification of tectorigenin to search for new compounds with anti-tumor activity. METHODS： Tectorigenin was used as a lead compound， and then added into amine reagents as ethanolamine， methylamine， ethylamine， dimethylamine， diethylamine， n-propylamine and formaldehyde solution. Tectorigenin Mannich base derivatives were synthesized by mannich reaction with as the lead compound. The structures of the derivatives were identified according to IR， UV， MS and NMR data. Solubility of tectorigenin and its derivatives were investigated by solubility test method. MTT assay was used to investigate the inhibitory effects of tectorigenin and its derivatives on the proliferation of human colon cancer cell line HCT116， human lung cancer cell line A549 and human hepatoma cell line HepG2， and half inhibitory concentration （IC50） was calculated. The inhibition rate of tectorigenin and its derivatives （100 mg/kg） on H22 hepatoma-bearing mice in vivo was studied. RESULTS： Totally of 6 kinds of tectorigenin mannich base derivatives were synthesized， such as 8-（N-hydroxyethyl）-methyleneamino-5，7，4′-trihydroxy-6-methoxyisoflavone， 8-（N-methyl）-methyleneamino-5，7，4′-trihydroxy-6- methoxyisoflavone， 8-（N， N-diethyl）-methyleneamino-5，7，4′-trihydroxy-6-methoxyisoflavone， 8-（N， N-dimethyl）-methyleneamino- 5，7，4′-trihydroxy-6-methoxyisoflavone， 8-（N-ethyl）-methyleneamino-5，7，4′-trihydroxy-6-methoxyisoflavone， 8-（N-propyl）- methyleneamino-5，7，4′-trihydroxy-6-methoxyisoflavone （compounds 1-6 in turn）. Compared with tectorigenin， the water solubility of six derivatives was significantly improved， and the solubility was 5-20 times higher than that of tectorigenin. IC50 of compounds 1， 3 and 5 to HCT116 cells were （34.82±3.27）， （16.21±4.13）， （33.12±3.25） μmol/L， which were stronger than that of tectorigenin [（45.23±5.74） μmol/L]； IC50 of compounds 1， 3 and 5 to A549 cells were （37.05±5.74）， （26.88±4.52）， （30.13±6.23） μmol/L， which were stronger than that of tectorigenin [（53.24±6.34） μmol/L]； IC50 of compounds 1， 3 and 5 to HepG2 cells were （23.74±1.45）， （18.96±2.34）， （30.95±2.87） μmol/L， which were stronger than that of tectorigenin [（48.98±2.58） μmol/L]. Compounds 1， 3 and 5 showed higher inhibition rates （55.51％， 57.20％ and 49.15％） than tectorigenin （33.05％） on H22 hepatoma-bearing mice， respectively. The other three compounds had no obvious advantage over tectorigenin in anti-tumor activity. CONCLUSIONS： In this study， compounds 1， 3 and 5 of six tectorigenin mannich base derivatives synthesized in this study have stronger antitumor activity than tectorigenin.

Estrogen receptor α and aryl hydrocarbon receptor cross-talk in a transfected hepatoma cell line (HepG2) exposed to 2,3,7,8-tetrachlorodibenzo-p-dioxin.

The prototype dioxin congener 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) is known to exert anti-estrogenic effects via activation of the aryl hydrocarbon receptor (AhR) by interfering with the regulation of oestrogen homeostasis and the estrogen receptor α (ERα) signalling pathway. The AhR/ER cross-talk is considered to play a crucial role in TCDD- and E2-dependent mechanisms of carcinogenesis, though the concerted mechanism of action in the liver is not yet elucidated. The present study investigated TCDD's impact on the transcriptional cross-talk between AhR and ERα and its modulation by 17ß-estradiol (E2) in the human hepatoma cell line HepG2, which is AhR-responsive but ERα-negative. Transient transfection assays with co-transfection of hERα and supplementation of receptor antagonists showed anti-estrogenic action of TCDD via down-regulation of E2-induced ERα signaling. In contrast, enhancement of AhR signaling dependent on ERα was observed providing evidence for increased cytochrome P450 (CYP) induction to promote E2 metabolism. However, relative mRNA levels of major E2-metabolizing CYP1A1 and 1B1 and the main E2-detoxifying catechol-O-methyltransferase were not affected by the co-treatments. This study provides new evidence of a TCDD-activated AhR-mediated molecular AhR/ERα cross-talk mechanism at transcriptional level via indirect inhibition of ERα and enhanced transcriptional activity of AhR in HepG2 cells.