Discovery of pyrazolone spirocyclohexadienone derivatives with potent antitumor activity.

Starting from easy accessible pyrazoletetrahydropyran acetals, a series of new pyrazolone spirocyclohexadienone derivatives were synthesized and assayed for antitumor activity. Compound 10s was identified to possess good antitumor activity. It could induce MDA-MB-231 cancer cell apoptosis in a concentration dependent manner and arrest the cell cycle progression mainly at the G1 phase.

Reduction of hemoglobin, not iron, inhibited maturation of red blood cells in male rats exposed to high intensity endurance exercises.

The existence of sports anemia, induced by strenuous or long-term exercise and characterized by decreases of red blood cells (RBCs), hemoglobin and iron content, remains to be doubtful. To observe the effects of endurance exercise on RBCs and explain the underlying reason, we designed this study by observing RBCs parameters and iron metabolism in 8-weeks training rats and effects of iron supplement or protein supplement on RBCs. Results showed that erythrocyte counts, hematocrit, mean corpuscular volume and hemoglobin content decreased while RBC distribution width increased in exercised rats at later stage during 8 weeks training. But the contents of serum iron and ferritin decreased only at 1-week and 2-week and returned to normal at 4-week and 8-week. Same as iron content, apparent iron absorption rate was declined at early stage but restored to normal level at 8-week, as well as serum adrenaline, cortisol and insulin levels. Instead, the contents of total protein and albumin in serum were decreased at later stage during 8-weeks training. Furthermore, we observed that protein supplement ameliorated RBCs parameters in rats exposed to 8 weeks swimming exercise, but iron supplement had no effects on RBCs, though it obviously increased iron content of serum and the liver. Based on these results, we drew a conclusion that transient changes of iron metabolism, which may be induced by stress hormone changes, was not the reason for RBCs decrease in endurance exercises but hemoglobin reduction, induced by defects in protein supplement, impeded development of RBCs.

HNF-4alpha Negatively Regulates Hepcidin Expression Through BMPR1A in HepG2 Cells.

Hepcidin synthesis is reported to be inadequate according to the body iron store in patients with non-alcoholic fatty liver disease (NAFLD) undergoing hepatic iron overload (HIO). However, the underlying mechanisms remain unclear. We hypothesize that hepatocyte nuclear factor-4α (HNF-4α) may negatively regulate hepcidin expression and contribute to hepcidin deficiency in NAFLD patients. The effect of HNF-4α on hepcidin expression was observed by transfecting specific HNF-4α small interfering RNA (siRNA) or plasmids into HepG2 cells. Both direct and indirect mechanisms involved in the regulation of HNF-4α on hepcidin were detected by real-time PCR, Western blotting, chromatin immunoprecipitation (chIP), and reporter genes. It was found that HNF-4α suppressed hepcidin messenger RNA (mRNA) and protein expressions in HepG2 cells, and this suppressive effect was independent of the potential HNF-4α response elements. Phosphorylation of SMAD1 but not STAT3 was inactivated by HNF-4α, and the SMAD4 response element was found essential to HNF-4α-induced hepcidin reduction. Neither inhibitory SMADs, SMAD6, and SMAD7 nor BMPR ligands, BMP2, BMP4, BMP6, and BMP7 were regulated by HNF-4α in HepG2 cells. BMPR1A, but not BMPR1B, BMPR2, ActR2A, ActR2B, or HJV, was decreased by HNF-4α, and HNF4α-knockdown-induced stimulation of hepcidin could be entirely blocked when BMPR1A was interfered with at the same time. In conclusion, the present study suggests that HNF-4α has a suppressive effect on hepcidin expression by inactivating the BMP pathway, specifically via BMPR1A, in HepG2 cells.

Facile construction of pyrrolo[1,2-b]isoquinolin-10(5H)-ones via a redox-amination-aromatization-Friedel-Crafts acylation cascade reaction and discovery of novel topoisomerase inhibitors.

An efficient redox-amination-aromatization-Friedel-Crafts acylation cascade process from trans-4-hydroxyproline and 2-formylbenzoic acids has been developed for the synthesis of pyrrolo[1,2-b]isoquinolin-10(5H)-ones. Compound 3h was identified as a new potent dual topoisomerase I/II inhibitor.

Hyperinsulinemia induces hepatic iron overload by increasing liver TFR1 via the PI3K/IRP2 pathway.

Dysmetabolic iron overload syndrome (DIOS) is frequently observed, but the underlying mechanism remains unclear. We propose the hypothesis that hyperinsulinemia, a common characteristic of DIOS, may stimulate liver transferrin receptor 1 (TFR1) expression via the PI3K/iron regulatory protein 2 (IRP2) pathway, leading to the occurrence of DIOS. The hepatic iron content, serum iron parameters, and expressions of TFRs and IRPs in the liver were determined in rats with temporary or long-lasting hyperinsulinemia induced by acute or chronic administration of insulin. The effect of insulin on TFR1 expression and its molecular mechanism were determined in HL-7702 cells in vitro. It was found that long-lasting hyperinsulinemia significantly increased TFR1 expression in the liver and induced mild-to-moderate hepatic iron overload, which was accompanied by a normal level of serum iron. Insulin markedly upregulated both protein and mRNA levels of TFR1 in HL-7702 cells. The stability of TFR1 mRNA stability, together with expression of IRPs expression, were both significantly increased by insulin treatment. Insulin-induced TFR1 expression was blocked by IRP2, but not by IRP1 interference, and disappeared when HL-7702 cells were pretreated with LY294002, triciribine hydrate, or rapamycin. In conclusion, the findings of this study indicate that hyperinsulnemia could induce hepatic iron overload by upregulating liver TFR1 via the PI3K/AKT/mTOR/IRP2 pathway, which may be one of the main reasons for the occurrence of DIOS.

Hepcidin is directly regulated by insulin and plays an important role in iron overload in streptozotocin-induced diabetic rats.

Iron overload is frequently observed in type 2 diabetes mellitus (DM2), but the underlying mechanisms remain unclear. We hypothesize that hepcidin may be directly regulated by insulin and play an important role in iron overload in DM2. We therefore examined the hepatic iron content, serum iron parameters, intestinal iron absorption, and liver hepcidin expression in rats treated with streptozotocin (STZ), which was given alone or after insulin resistance induced by a high-fat diet. The direct effect of insulin on hepcidin and its molecular mechanisms were furthermore determined in vitro in HepG2 cells. STZ administration caused a significant reduction in liver hepcidin level and a marked increase in intestinal iron absorption and serum and hepatic iron content. Insulin obviously upregulated hepcidin expression in HepG2 cells and enhanced signal transducer and activator of transcription 3 protein synthesis and DNA binding activity. The effect of insulin on hepcidin disappeared when the signal transducer and activator of transcription 3 pathway was blocked and could be partially inhibited by U0126. In conclusion, the current study suggests that hepcidin can be directly regulated by insulin, and the suppressed liver hepcidin synthesis may be an important reason for the iron overload in DM2.