We have revealed that in Caenorhabditis elegans, non-sulfated chondroitin is required for normal cell division and cytokinesis at an early developmental stage, whereas heparan sulfate is essential for embryonic morphogenesis in the later stages of development. To clarify the roles of chondroitin sulfate and heparan sulfate in early embryogenesis in mammals, we generated glucuronyltransferase-I (GlcAT-I) knock-out mice by gene targeting. GlcAT-I is an enzyme required for the synthesis of both chondroitin sulfate and heparan sulfate. Here we report that mice with a deletion of GlcAT-I showed remarkable reduction of the synthesis of chondroitin sulfate and heparan sulfate and embryonic lethality before the 8-cell stage because of failed cytokinesis. In addition, treatment of wild-type 2-cell embryos with chondroitinase ABC had marked effects on cell division, although many heparitinase-treated embryos normally developed to blastocysts. Taken together, these results suggest that chondroitin sulfate in mammals, as with non-sulfated chondroitin in C. elegans, is indispensable for embryonic cell division.

Chondroitin sulfate (CS)/chondroitin (Chn) chains are indispensable for embryonic cell division and cytokinesis in the early developmental stages in Caenorhabditis elegans and mice, whereas heparan sulfate (HS) is essential for axon guidance during nervous system development. These data indicate that the fundamental functions of CS and HS are conserved from worms to mammals and that the function of CS/Chn differs from that of HS. Although previous studies have shown that C. elegans produces HS and non-sulfated Chn, whether the organism produces CS remains unclear. Here, we demonstrate that C. elegans produces a small amount of 4-O-sulfated Chn and report the identification of C41C4.1, an orthologue of the human chondroitin 4-O-sulfotransferase gene. Loss of C41C4.1 in C. elegans resulted in a decline in 4-O-sulfation of CS and an increase in the number of sulfated units in HS. C41C4.1 deletion mutants exhibited reduced survival rates after synchronization with sodium hypochlorite. Collectively, these results show for the first time that CS glycans are present in C. elegans and that the Chn 4-O-sulfotransferase responsible for the sulfation plays an important role in protecting nematodes from oxidative stress.

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The anti-tumor agent gemcitabine hydrochloride is stable in solid state; however, deamination occurs in acidic solution, yielding β-uridine analogue, whereas anomerization reaction occurs in basic solution. Thus, the brandname preparation for injection is supplied as lyophilized dry powder, and ingredients are added to result in acidic solution when dissolved in saline. In this study, a brand-and 6 generic-name medicines were compared with regard to gemcitabine stability, β-uridine production, and pH during storage at 25℃ for 6 months after dissolving in saline. Gemcitabine concentrations were decreased time-dependently, and β-uridine concentrations were increased. The pH values were constant. Another generic medicine supplied as solution was also subjected for comparison. At the start of the experiments (Time 0), β-uridine had already been produced in the generic medicine supplied as solution. These results suggest that the generic medicine supplied as solution has to be maintained for tight control in the processes of manufacturing or distribution.

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