Research progress of heparinase in the field of medicine / 生物工程学报

Heparinases can produce biologically active oligosaccharides by specifically cleaving the α-(1,4) glycosidic linkages of heparin and heparan sulphate. Heparinases are divided into heparinase and heparanase. Because heparinase is an effective biocatalyst, more and more researchers pay attention to the application of heparinase in medical field in the recent years. Combined with the related research work in our group, the application value of heparinase in the medical field was summarized, such as the determination of the structure of heparin, the preparation of low-molecular-weight heparin and ultra-low-molecular-weight heparin, tumor therapy and as a heparin antagonist. In addition, we summarized the definition, source of heparinase and its application in the medicine field. Heparinases have a great application prospect in the field of medicine.

Protective Effect of Ultra Low Molecular Weight Heparin on Glutamate-Induced Apoptosis in Cortical Cells

PURPOSE: To investigate the effect of ultra low molecular weight heparin (ULMWH) on glutamate induced apoptosis in rat cortical cells and to explore the possible mechanisms. MATERIALS AND METHODS: Cell viability was measured using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. Apoptosis was first analyzed with Hoechst 33258 and then confirmed by DNA fragmentation. The concentration of free intracellular calcium ([Ca2+](i)) was determined with fura-2/AM fluorometry. The expression of Bcl-2 family protein and caspase-3 were evaluated with Western blot. RESULTS: Typical apoptotic morphological change in rat cortical cells treated with 100micromol/L glutamate for 24h was detected by Hoechst 33258 staining, which was then confirmed by the DNA ladder of agarose gel electrophoresis. The apoptotic rate of the glutamate treated cells was up to 33.21%, and 24 h of treatment with glutamate increased [Ca2+](i), down-regulated Bcl-2 expression, up-regulated Bax expression, and increased caspase-3 activation in rat cortical cells. Our research demonstrated that ULMWH pretreatment can prevent the glutamate- induced apoptosis, attenuate the increase of [Ca2+](i) not only in medium containing Ca2+ but also in Ca2+-free medium, up-regulate the expression of Bcl-2, down-regulate the expression of Bax, and decrease caspase-3 activation. CONCLUSION: ULMWH has neuroprotective capacity to antagonize glutamate-induced apoptosis in cortical cells, through decrease of Ca2+ release and modulation of apoptotic processes.

Ultra low molecular weight heparin attenuates glutamate-induced neurotoxicity by reducing intracellular calcium release / 中国药理学通报

Aim To investigate the effect of ultra low molecular weight heparin(ULMWH)to protect primarily cultured rat cortical neurons from the deleterious effects of the neurotoxicant glutamate (Glu)and explore the related mechanism.Methods Cortical neurons of fetal rats were cultured carefully in vitro and treated with 100 ?mol?L-1 Glu so that the protective effects of ULMWH were observed thoroughly. And then the viability of cortical neurons, morphological change together with the number of apoptotic neurons,and the concentration of intracellular free Ca2+([Ca2+]i)were measured by MTT assay, Hoechst33258 staining and Fura-2/AM double wavelength fluoremetry, respectively.Results Brief exposure of cultures to 100 ?mol?L-1Glu led to extensive neuronal death and rapid increase of [Ca2+]i.Pretreatment with ULMWH over the concentration range of 0.01~1 mg?L-1 significantly inhibited the Glu-induced neuronal cell death assessed by a MTT assay and the number of apoptotic nuclei, evidenced by Hoechst 33258 staining.Glu-induced elevation of[Ca2+]i was decreased by pretreatment with 1 mg?L-1 ULMWH, which was indicated by Fura-2/AM not only in assay medium containing Ca2+ but also in Ca2+-free assay medium.Conclusions Those results suggest that ULMWH protects the cultured neurons from Glu-induced neurotoxicity, which may be attributed to its alleviating intracellular free Ca2+ overload via suppressing intracellular Ca2+ release from internal stores induced by Glu.