1.Effect of Activating Blood to Resolve Stagnation on Cells Expressing CD34 and Vascular Endothelial Growth Factor in Rats with Acute Myocardial Infarction
Wei SHI ; Yezi LI ; Haibin ZHAO ; Dandan YANG ; Tianyuan JIANG ; Dongfang LI ; Yaoyao ZHAI
Chinese Journal of Rehabilitation Theory and Practice 2015;21(8):894-899
Objective To explore the effect of Activating Blood to Resolve Stagnation on the expression of CD34 and vascular endothelial growth factor (VEGF) in rats with acute myocardial infarction. Methods 32 Sprague-Dawley rats were randomly divided into sham operation group (A, n=8), model group (B, n=8), Xuesaitong Injection + granulocyte colony- stimulating factor (G- CSF) group (C, n=8) and G-CSF group (D, n=8). Corresponding medicine was given to each group 3 hours after modeling, for 6 days. Pathomorphological changes were observed through HE staining, and the expression of CD34, VEGF and Ki-67 were observed through immunohistochemical staining. Results The expressions of CD34, VEGF and Ki-67 were higher in groups B, C and D than in group A (P<0.05), and were higher in group groups C and D than in group B (P<0.05). The expressions of CD34 and VEGF were higher in group C than in group D (P<0.05). However, there was no significant difference in the expression of Ki-67 between 2 groups (P>0.05). Conclusion The expression of CD34 and VEGF increases with Activating Blood to Resolve Stagnation method, which is superior to using G-CSF only. Activating Blood to Resolve Stagnation may play an important role in the treatment of acute myocardial infarction.
2.Molecular chaperones facilitate soluble expression of recombinant non-toxic mutant CRM197 of diphtheria toxin in Escherichia coli.
Mengting YANG ; Xiaoxiao LI ; Chen LIN ; Mingjing LIU ; Yezi CHEN ; Yun ZHAO ; Chaoqi LIU
Chinese Journal of Biotechnology 2021;37(4):1368-1375
Diphtheria toxin is an ADP-ribosyltransferase toxic to human cells. Mutation of the active site in its catalytic domain eliminates the toxicity, but retains its immunogenicity. A non-toxic mutant of diphtheria toxin known as CRM197 protein has become an ideal carrier protein for conjugate vaccines. CRM197 can further improve its immunogenicity by cross-linking with other antigens, so it has good potential to find broad applications. Unfortunately, inclusion bodies are easily formed during the expression of recombinant CRM197 protein in Escherichia coli, which greatly reduces its yield. In order to address this problem, pG-KJE8 vector carrying molecular chaperones and plasmid pET28a-CRM197, were co-expressed in Escherichia coli. The results showed that the recombinant CRM197 protein was successfully expressed and appeared largely in inclusion bodies. The molecular chaperones DnaK, DnaJ, GrpE, GroES and GroEL5 expressed can facilitate correct and rapid folding of CRM197. Furthermore, it can also improve the recovery rate of soluble CRM197 protein. The soluble expression of CRM197 was maximized upon addition of 1.0 mmol/L IPTG, 0.5 mg L-arabinose, 5.0 ng/mL tetracycline and induction at 20oC for 16 h. The soluble CRM197 protein shows good immunoreactivity, demonstrating the molecular chaperones expressed from pG-KJE8 facilitated the soluble expression of CRM197 protein in E. coli.
Bacterial Proteins
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Diphtheria Toxin/genetics*
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Escherichia coli/genetics*
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Humans
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Molecular Chaperones/genetics*
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Recombinant Proteins/genetics*