Developmental toxicity of Cry1Ab protein in the embryonic stem-cell model / 北京大学学报(医学版)

Objective:To evaluate the developmental toxicity of Cry1Ab protein by studying its effects on cell proliferation and differentiation ability using a developmental toxicity assessment model based on embryonic stem-cell.Methods:Cry1Ab protein was tested in seven dose groups(31.25,62.50,125.00,250.00,320.00,1 000.00,and 2 000.00 μg/L)on mouse embryonic stem cells D3(ES-D3)and 3T3 mouse fibroblast cells,with 5-fluorouracil(5-FU)used as the positive control and phos-phate buffer saline(PBS)as the solvent control.Cell viability was detected by CCK-8 assay to calculate the 50％inhibitory concentration(IC50)of the test substance for different cells.Additionally,Cry1 Ab protein was tested in five dose groups(125.00,250.00,320.00,1 000.00,and 2 000.00 μg/L)on ES-D3 cells,with PBS as the solvent control and 5-FU used for model validation.After cell treatment,cardiac differentiation was induced using the embryonic bodies(EBs)culture method.The growth of EBs was observed under a microscope,and their diameters on the third and fifth days were measured.The proportion of EBs differentiating into beating cardiomyocytes was recorded,and the 50％inhibition con-centration of differentiation(ID50)was calculated.Based on a developmental toxicity discrimination func-tion,the developmental toxicity of the test substances was classified.Furthermore,at the end of the cul-ture period,mRNA expression levels of cardiac differentiation-related markers(Oct3/4,GATAA-4,Nkx2.5,and β-MHC)were quantitatively detected using real-time quantitative polymerase chain reaction(qPCR)in the collected EBs samples.Results:The IC50 of 5-FU was determined as 46.37 μg/L in 3T3 cells and 32.67 μg/L in ES-D3 cells,while the ID50 in ES-D3 cells was 21.28 μg/L.According to the discrimination function results,5-FU was classified as a strong embryotoxic substance.There were no sta-tistically significant differences in cell viability between different concentrations of Cry 1 Ab protein treat-ment groups and the control group in both 3T3 cells and ES-D3 cells(P＞0.05).Moreover,there were no statistically significant differences in the diameter of EBs on the third and fifth days,as well as their morphology,between the Cry1Ab protein treatment groups and the control group(P＞0.05).The cardi-ac differentiation rate showed no statistically significant differences between different concentrations of Cry1Ab protein treatment groups and the control group(P＞0.05).5-FU significantly reduced the mRNA expression levels of β-MHC,Nkx2.5,and GATA-4(P＜0.05),showing a dose-dependent trend(P＜0.05),while the mRNA expression levels of the pluripotency-associated marker Oct3/4 exhibited an increasing trend(P＜0.05).However,there were no statistically significant differences in the mRNA expression levels of mature cardiac marker β-MHC,early cardiac differentiation marker Nkx2.5 and GATA-4,and pluripotency-associated marker Oct3/4 between the Cry1Ab protein treatment groups and the control group(P＞0.05).Conclusion:No developmental toxicity of Cry1Ab protein at concen-trations ranging from 31.25 to 2 000.00 μg/L was observed in this experimental model.

Study on the effects and mechanism of luteolin on osteogenic repair of bone defects / 中国药房

OBJECTIVE To investigate the effects and mechanism of luteolin on osteogenic repair of bone defects. METHODS The targets and potential pathways of luteolin in the treatment of bone defects were screened by network pharmacology method， and then the top 2 targets were selected by Hub gene screening for molecular docking verification， with binding energy as the evaluation standard. In vitro experiments were conducted on rat bone mesenchymal stem cells （BMSC） and rat umbilical vein endothelial cells （RUVEC）. Phenotypic validation was performed using alkaline phosphatase staining， alizarin red S staining， and in vitro angiogenesis experiments. Western blot assay was used to detect the protein expressions of phosphatidylinositol 3 kinase （PI3K） and protein kinase 1 （Akt1）， so as to validate the mechanism of luteolin on osteogenic differentiation of BMSC and angiogenesis of RUVEC in vitro. RESULTS The results of network pharmacology showed that the effects of luteolin on vascular formation and bone repair in bone defects were mainly related to Akt1， SRC， estrogen receptor 1， epidermal growth factor receptor， cyclooxygenase 2， matrix metalloproteinase 9 targets， and were closely related to PI3K-Akt signaling pathway. The results of molecular docking showed that luteolin binding to Akt1 and SRC proteins was stable. The results of in vitro experiments showed that luteolin could significantly improve the expressions and activities of alkaline phosphatase in BMSC， increased the number of calcium salt deposits and calcified nodules， and promoted calcification of BMSC. Compared with luteolin 0 μmol/L group， the angiogenesis ability of RUVEC was enhanced significantly in luteolin 1， 10 μmol/L groups， the length of blood vessels and the protein expressions of PI3K and Akt1 were significantly increased （P＜0.05 or P＜0.01）； the higherthe concentration， the better the effect. CONCLUSIONS Luteolin may play a role in promoting angiogenesis and bone repair at the fracture site by activating PI3K/Akt signaling pathway and promoting the protein expressions of PI3K and Akt1.

Lipase nanogel catalyzed synthesis of vitamin E succinate in non-aqueous phase.

BACKGROUND: In order to improve the stability of vitamin E and broaden its scope of application, an effective solution is to convert vitamin E into its derivatives. This work developed a new Candida rugosa lipase (CRL) nanogel based on modification of ionic liquid with vinyl functional groups. This novel CRL nanogel was used in the preparation process of vitamin E succinate based on the principle of non-aqueous enzymology. At the same time, various factors including enzyme concentration, substrate molar ratio, reaction temperature and reaction time, that affect the yield of vitamin E succinate were optimized and analyzed. RESULTS: Different solvents with various hydrophobicity parameters (LogP values) from -1.3 to 3.5 were studied, it was found that dimethyl sulfoxide (DMSO) had the lowest LogP value among organic solvents but vitamin E succinate had the highest yield in DMSO. Furthermore, the effect of different operating conditions, such as molar ratios of substrate, enzyme concentration, reaction temperature and reaction time was studied. Under the optimal process conditions (enzyme concentration 6 mg mL-1 , substrate molar ratio 4:1, reaction temperature 55 °C and reaction time 15 h), the product yield was 62.58 ± 1.16%. CRL and CRL nanogel were characterized using Fourier-transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM). It was shown that CRL nanogel influenced the catalytic behavior of lipase significantly by changing the structure and surface properties of CRL. CONCLUSION: Novel lipase nanogel was an excellent biocatalyst for enzymatic synthesis of vitamin E succinate. © 2020 Society of Chemical Industry.

Increasing the Production of IgG in Batch Tissue-culture with IgG-free Ascites / 中国生物工程杂志

An effective method has been developed for laboratory scale production of IgG. Hybridomas were cultured in serum-free media with 2% IgG-free ascites. Cell density of up to 3.55 × 10 6cells/ml and antibody concentration of 135μ g/ml after purification were abtained, which is four time more than total production of that of IgG concentration in serum-free media. This in vitro method allows great improvement in antibodies production in batch tissue culture. The method reported here is easy to handle and is economical and universally adaptable.