A retinoic acid receptor agonist tamibarotene suppresses iron accumulation in the liver.

OBJECTIVE: Hepatic iron overload (HIO) and iron-induced oxidative stress have recently emerged as an important factor for the development and progression of insulin resistance. The aim of this study was to evaluate the effect of tamibarotene, a selective retinoic acid receptor α/ß agonist, on hepatic iron metabolism, based on our previous findings that retinoids suppress hepatic iron accumulation by increasing hepatic iron efflux through the regulation of hemojuvelin and ferroportin expression. DESIGN AND METHODS: We quantitated the non-heme iron content and iron metabolism-related gene expression in the liver, and serum lipid and blood glucose levels in KK-A(y) mice after dietary administration of tamibarotene. RESULTS: It was demonstrated that tamibarotene significantly reduced blood glucose and hepatic iron, but not serum lipids, and that hemojuvelin expression significantly decreased while ferroportin increased, as observed previously. CONCLUSIONS: These results suggest that tamibarotene is a promising alternative for the treatment of insulin resistance associated with HIO.

Triaryl(1-pyrenyl)bismuthonium salts: efficient photoinitiators for cationic polymerization of oxiranes and a vinyl ether.

Photoirradiation of triaryl(1-pyrenyl)bismuthonium salts in acetonitrile afforded triarylbismuthanes and pyrene, accompanied by the generation of protic acids. Triaryl(1-pyrenyl)bismuthonium hexafluoroantimonates have proven to behave as efficient photoinitiators for cationic polymerization of oxiranes and a vinyl ether, affording the corresponding polymers in good yields within 1 min.

The cbs mutant strain of Rhodococcus erythropolis KA2-5-1 expresses high levels of Dsz enzymes in the presence of sulfate.

Two mutants of the dibenzothiophene-desulfurizing Rhodococcus erythropolis KA2-5-1, strains MS51 and MS316, which express a high level of desulfurizing activity in the presence of sulfate, were isolated using the transposome technique. The level of dibenzothiophene-desulfurization by cell-free extracts prepared from mutants MS51 and MS316 grown on sulfate was about five-fold higher than that by cell-free extracts of the wild-type. This result was consistent with results of Western-blot analysis using antisera specific for DszA, DszB and DszC, the enzymes involved in the desulfurization of dibenzothiophene. Gene analysis of the mutants revealed that the same gene was disrupted in mutants MS51 and MS316 and that the transposon-inserted gene in these strains was the gene for cystathionine beta-synthase, cbs. The cbs mutants also expressed high levels of Dsz enzymes when methionine was used as the sole source of sulfur.