Combinational expression of geranylgeranyl diphosphate synthase and taxadiene synthase in Coprinopsis cinerea / 生物工程学报

Taxa-4(5),11(12)-diene is the precursor for paclitaxel biosynthesis. The diterpenoid paclitaxel (marketed as Taxol), a plant secondary metabolite isolated from yew, is an effective drug widely used in the treatment of numerous cancers. However, further application of taxol has been restricted due to its low yield in plants and the difficulties in extraction. To increase the intact isoprene flux, we constructed the fusion gene plasmid pBgGGTS and individual cassette plasmid pBgGGgTS to enhance the expression levels of geranylgeranyl diphosphate synthase gene (ggpps) and a taxadiene synthase gene (ts) in Coprinopsis cinerea. These two plasmids were separately transformed into C. cinerea LT2 strain, resulting in several putative transformants. Putative transformants were determined by PCR technique, indicating that 5 out of 13 putative transformants transformed by pBgGGTS and 6 out of 13 putative transformants transformed by pBgGGgTS, respectively. Additionally, the Southern blotting analysis of these 10 transformants confirmed that both ggpps and ts gene were stably integrated into the genome of C. cinerea. Crude extracts from each of the transformants were analyzed. There is no difference in the mycelium extracts among the wild-type LT2 and two types of transformants. However, analysis of culture filtrates indicated that an additional GC peak was found at the retention time of 16.762 min which was absent in the wild type control. The mass fragmentation pattern of this peak had the same diagnostic ions with taxa-4(5),11(12)-diene. According to peak area, the amounts of taxa-4(5),11(12)-diene in each fermented broth were 44 ng/L (transformed with pBgGGgTS) and 30 ng/L (transformed with pBgGGTS), respectively. In conclusion, co-expression of the ggpps and ts gene could increase the taxadiene production in C. cinerea.

The clinical significance of advanced oxidation protein products in patients with systemic lupus erythematosus complicated with atherosclerosis praecox / 中华风湿病学杂志

Objective To estimate the degree of oxidative stress and atherosclerosis praecox in patients with systemic lupus erythematosus (SLE), and emphasize on exploring AOPPs' clinical significance in premature atherosclerosis in SLE. Methods The levels of AOPPs, Hey, MDA, SOD, baPMV and CIMT were detected by ELISA and spectropholometry in 44 non-menopausal female SLE patients and 31 healthy middle-aged women respectively, and baPWV. The results were compared with AOPPs of the two groups. Then each group was stratified based on disease duration (≥5 years or <5 years) and the disease activity(active and inactive) in SLE patients. The patients' TC, TG, LDL were analyzed. T test, t' test and Pearson correla-tion were selected. Results The levels of AOPPs, Hcy, MDA in SLE patients were significantly higher than those of the healthy controls (P<0.05). The activities of SOD were lower than controls (P<0.05). The levels of AOPPs, Hcy, MDA, SOD had statistical significance between SLE patients disease duration ≥5 years or <5 years, active or inactive groups. There were two cases with CAP in patients with SLE (more than 5 years disease duration),while there wasnone in healthy controls. The levels of baPWV and CIMT in patients with SLE were higher than healthy controls (P<0.05), and had statistical significance in SLE patients disease duration more than or less than 5 years (P<0.05). The oxidative stress targets (AOPPs, Hey, MDA, SOD) had significant correlation with the level of baPWV and CIMT (P<0.01). The level of serum AOPPs had significant positive correlation with the levels of Hcy, TC, TG and LDL (P<0.01～0.05). Conclusion SLE patients have increased oxidative stress , and significantly higher prevalence of atherosclerosis than healthy controls. The disease duration and oxidative stress play important roles in the duration of atherosclerosis. AOPPs probably involves in the accelerated atherosclerosis of SLE patients. It may be a predictor for SLE complicated with atherosclerosis praecox.