Inhibitory effect of antimicrobial peptide LL-37 on tumor growth of mice with colon cancer and its mechanism / 吉林大学学报(医学版)

Objective: To investigate the effects of antimicrobial peptide LL-37 on the tumor growth and apoptosis of the mice with colon cancer, and to elucidate the possible molecular mechanism of its anti-tumor effect. Methods: The LL-37 over-expression colon cancer HT-29 cells were constructed, and the expression levels of LL-37 mRNA and protein in the HT-29 cells were detected by qRT-PCR and Western blotting methods. A total of 30 BALB/c mice were randomly divided into control group (given the uninfected HT-29 cells)' empty vector group (given the HT-29 cells infected with empty plasmid), LL-37 over-expression group (given the HT-29 cells infected with LL-37 over-expression vector), AMPK inhibitor group [given the HT-29 cells infected with empty vector, and then injected with 2 mg • kg Dorsomorphin (Dor) in the tail vein

Changes and clinical significance of antimicrobial peptide LL-37 and CRP in patients with Pseudomonas aeruginosa positive sputum culture / 国际检验医学杂志

Objective To investigate the changes of antimicrobial peptide LL-37 and C-reactive protein (CRP ) in the patients with Pseudomonas aeruginosa positive sputum culture and their mutual relation . Methods Fifty cases of Pseudomonas aeruginosa positive sputum culture and 27 cases undergoing physical ex-amination in the Guangdong Provincial Hospital of Chinese Medicine from September 2016 to May 2017 were selected as the research subjects .The level of antimicrobial peptide LL-37 was detected by double antibody sandwich ELISA and the CRP level was detected by immunoturbidimetry .Results The levels of antimicrobial peptide LL-37 and CRP in the Pseudomonas aeruginosa positive sputum culture group were significantly high-er than those in the healthy control group ,the difference was statistically significant (P< 0 .05) ,and they showed the positive correlation (r=0 .411 ,P<0 .05) .Conclusion In positive sputum culture of Pseudomonas aeruginosa ,antimicrobial peptide LL-37 and CRP levels are increased ,which has a certain clinical application value for the early diagnosis of infection .

Modification of 5′-UTR sequences of pPIC9 increases expression of antimicrobial peptide LL-37 / 第二军医大学学报

Objective: To study the influence of 5′-untranslated region modification of pPIC9 on expression of LL-37 in Pichia pastoris. Methods: The sequence GGATCCAA was deleted from 5′-UTR of pPIC9 and the modified product was transformed into E. coli DH5α to construct a modified eukaryotic vector pPIC9-EDIT. After PCR and sequencing, pPIC9-EDIT was ligated with LL-37 sequence coded by the biased codon of yeast, the product was then transformed into E. coli DH5α to construct the recombinant expression vector pPIC9-EDIT-LL-37, the latter was transformed into P. pastoris GS115 by spheroplasting and the insert was confirmed by PCR. The bacteriolytic activity to E. coli. DH5α was analyzed to screen the highest expressing strain and to determine the best inducing time and concentration of methanol. The fermentation product was analyzed by Tricine-SDS-PAGE and Western blotting. The antibacterial activities of expression products of pPIC9-LL-37 and pPIC9-EDIT-LL-37 were compared, and the changes of LL-37 protein expression were determined before and after modification. Results: pPIC9-EDIT and pPIC9-EDIT-LL-37 were successfully constructed. Expression of LL-37 gene was confirmed by PCR in P. pastoris after pPIC9-EDIT-LL-37 transformation. The highest expressing strain was identified; the best inducing time was 72 h and the best concentration of methanol was 0.5%. Tricine-SDS-PAGE and Western blotting analysis showed that the expression product was LL-37. The expression level of LL-37 protein increased by 35 times after modification. Conclusion: Modification of pPIC9 5′-UTR can obviously improve expression of LL-37 protein in P. pastoris; it is worth to be used in the research of other heterogenous protein.

Modification of 5′-UTR sequences of pPIC9 increases expression of antimicrobial peptide LL-37 / 第二军医大学学报

Objective:To study the influence of 5′-untranslated region modification of pPIC9 on expression of LL-37 in Pichia pastoris.Methods:The sequence GGATCCAA was deleted from 5′-UTR of pPIC9 and the modified product was trans- formed into E.coli DH5?to construct a modified eukaryotic vector pPIC9-EDIT.After PCR and sequencing,pPIC9-EDIT was ligated with LL-37 sequence coded by the biased codon of yeast,the product was then transformed into E.coli DH5?to con- struct the recombinant expression vector pPIC9-EDIT-LL-37,the latter was transformed into P.pastoris GS115 by spheroplas- ting and the insert was confirmed by PCR.The bacteriolytic activity to E.coli.DH5?was analyzed to screen the highest ex- pressing strain and to determine the best inducing time and concentration of methanol.The fermentation product was analyzed by Tricine-SDS-PAGE and Western blotting.The antibacterial activities of expression products of pPIC9-LL-37 and pPIC9-ED- IT-LL-37 were compared,and the changes of LL-37 protein expression were determined before and after modification.Results: pPIC9-EDIT and pPIC9-EDIT-LL-37 were successfully constructed.Expression of LL-37 gene was confirmed by PCR in P.pastoris after pPIC9-EDIT-LL-37 transformation.The highest expressing strain was identified;the best inducing time was 72 h and the best concentration of methanol was 0.5%.Tricine-SDS-PAGE and Western blotting analysis showed that the ex- pression product was LL-37.The expression level of LL-37 protein increased by 35 times after modification.Conclusion:Modifi- cation of pPIC9 5′-UTR can obviously improve expression of LL-37 protein in P.pastoris;it is worth to be used in the research of other heterogenous protein.