1.Construction, expression and enzymatic activity analysis of AUR1 eukaryotic expression vector of Botrytis cinerea.
Yongchun QIU ; Xiaoping LIU ; Ping GOU
Chinese Journal of Biotechnology 2013;29(1):78-86
In order to study the expression and the activity of inositol phosphorylceramide synthase (BcAUR1 gene) in Botrytis cinerea, we amplified BcAUR1 by RT-PCR from Botrytis cinerea, using the special primers with FLAG and BamH I/Xho I restriction sites. Recombinant pYES2-BcAUR1 was constructed to transform into Saccharomyces cerevisae deltayorl by LiAC. The expression of inositol phosphorylceramide (IPC) synthase and its activity were detected by Western blotting and HPLC, respectively. The results show that pYES2-BcAUR1 could express in uracil mutant deltayorl of Saccharomyces cerevisae. IPC synthase enzyme activity of pYES2-BcAUR1 transformants significantly increased and was approximately double than no-load BcAUR1 transformants. The low concentration of Aureobasidin A could inhibit growth of no-load BcAUR1 transformants, but pYES2-BcAUR1 transformants could resist fungal growth inhibition which was induced by Aureobasidin A.
Botrytis
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enzymology
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genetics
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Depsipeptides
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pharmacology
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Fungal Proteins
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genetics
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metabolism
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Gene Expression
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Genetic Vectors
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Hexosyltransferases
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genetics
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metabolism
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Saccharomyces cerevisiae
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genetics
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metabolism
2.Effects of fluoride exposure on proliferation, apoptosis and osteogenic differentiation of mouse bone marrow mesenchymal stem cells
Yinfeng QIU ; Minzhi YANG ; Yihan WU ; Jinhua YU ; Yongchun GU
Chinese Journal of Endemiology 2022;41(10):801-808
Objective:To investigate the effects of fluoride exposure on proliferation, apoptosis and osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) in mice.Methods:BMSCs were isolated and cultured from femur bone marrow of C57BL/6 mice (6 - 8 weeks). The cells in passage 3 were used to detect the surface markers of stem cells by flow cytometry. The cells were cultured in media with a final fluoride concentration of 0.0, 0.1, 1.0, 5.0, 10.0, 15.0, 20.0 and 40.0 mg/L, respectively. The effects of different fluoride concentrations on BMSCs cell proliferation (CCK8 method), apoptosis (flow cytometry analysis), osteogenic differentiation ability [alizarin red and alkaline phosphatase (ALP) staining] were detected. Western blot was applied to detect the levels of apoptosis-related proteins [poly ADP-ribose polymerase (PARP)], mitogen-activated protein kinase (MAPK) pathway member proteins [extracellular regulated protein kinase 1/2 (ERK1/2), c-Jun amino-terminal kinase (JNK), p38 and phosphorylated ERK, JNK, p38 (p-ERK, p-JNK, p-p38)], osteogenic differentiation-related protein [Runt-related transcription factor 2 (Runx2), ALP] and Wnt/β-catenin pathway member proteins [glycogen synthase kinase-3β (GSK3β), phosphorylated GSK3β (p-GSK3β) and β-catenin]. Immunocytofluorescense staining was applied to evaluate the expression levels of p-GSK3β and β-catenin. The two pathways (MAPK and Wnt/β-catenin) were blocked by SP600125 and DKK-1, respectively, to testify their involvement in mechanisms of apoptosis and osteogenic differentiation.Results:The mouse BMSCs were successfully isolated and cultured. Flow cytometry analysis showed that the mesenchymal stem cell surface biomarkers (CD73, CD90 and CD105) were positively expressed. The comparison of cell proliferation at three time points (24, 48 and 72 h) in each concentration group was statistically significant ( F = 65.36, 160.04 and 365.32, P < 0.001), and the comparison of early apoptosis (24 h) in each concentration group was statistically significant ( F = 214.04, P < 0.001); compared with the 0.0 mg/L group, the cell proliferation in 15.0, 20.0 and 40.0 mg/L groups decreased, and the early apoptosis rate in 10.0, 15.0 and 20.0 mg/L groups increased ( P < 0.05). When cells were treated with 15.0 mg/L fluoride for 0 - 24 h, the p-JNK/JNK ratio was higher at 2, 4, 8, 12, 18 and 24 h compared with that at 0 min ( P < 0.05); compared with the fluoride group (15.0 mg/L), the early apoptosis rate of cells after SP600125 block decreased ( P < 0.05), and the protein expression levels of PARP and p-JNK decreased ( P < 0.05). After osteogenic induction, compared with the 0.0 mg/L group, in 0.1 and 1.0 mg/L groups ALP staining was enhanced and the number of calcified nodules increased, and the protein expression levels of Runx2 and ALP in the 0.1 and 1.0 mg/L groups were higher ( P < 0.05). After osteogenic induction, compared with the 0.0 mg/L group, the p-GSK3β/GSK3β ratio and β-catenin protein level were significantly higher in the 0.1 and 1.0 mg/L groups ( P < 0.05); and compared with the fluoride group (1.0 mg/L), addition of DKK-1 significantly decreased the protein expression levels of p-GSK3β and β-catenin and reduced the nuclear entry of β-catenin, and ALP staining decreased and the number of calcified nodules decreased. Conclusions:High concentration of fluoride (> 10.0 mg/L) inhibits the proliferation and promotes apoptosis of BMSCs, while low concentration of fluoride (0.1, 1.0 mg/L) promotes osteogenic differentiation. The MAPK/JNK pathway and the classical Wnt pathway are involved in the above cellular processes, respectively.