ABSTRACT
OBJECTIVE@#To investigate the potential mechanisms that mediate the inhibitory effect of porcine recombinant NKlysin (prNK-lysin) against liver cancer cell metastasis.@*METHODS@#HPLC-tandem mass spectrometry was used to identify the differentially expressed proteins in prNK-lysin-treated hepatocellular carcinoma SMMOL/LC-7721 cells in comparison with the control and PBS-treated cells. GO functional annotation and KEGG pathway analysis of the differentially expressed proteins were performed using GO and KEGG databases. RT-qPCR was used to determine the mRNA expression levels of polypeptide-N-acetylgalactosaminotransferase 13 (GALNT13), transmembrane protein 51 (TMEM51) and FKBP prolyl isomerase 3 (FKBP3) in the cells, and the protein expression of FKBP3 was verified using Western blotting.@*RESULTS@#Proteomic analysis identified 1989 differentially expressed proteins in prNK-lysin-treated cells compared with the control cells, and 2753 compared with PBS-treated cells. Fifteen proteins were differentially expressed between PBS-treated and the control cells, and 1909 were differentially expressed in prNK- lysin group compared with both PBS and control groups. These differentially expressed proteins were involved mainly in the viral process, translational initiation and RNA binding and were enriched mainly in ribosome, protein process in endoplasmic reticulum, and RNA transport pathways. RT-qPCR showed that compared with the control group, prNK-lysin treatment significantly increased the mRNA expressions of GALNT13 (P < 0.05) and TMEM51 (P < 0.01) and lowered FKBP3 mRNA expression (P < 0.05). Western blotting also showed a significantly decreased expression of FKBP3 protein in prNK-lysin-treated cells (P < 0.001).@*CONCLUSION@#Treatment with prNK-lysin causes significant changes in protein expression profile of SMMOL/LC-7721 cells and inhibits hepatocellular carcinoma metastasis by downregulating FKBP3 protein and affecting the cellular oxidative phosphorylation and glycolysis pathways.
Subject(s)
Animals , Swine , Carcinoma, Hepatocellular/pathology , Liver Neoplasms/pathology , Oxidative Phosphorylation , Proteomics , Glycolysis , RNA, MessengerABSTRACT
Bacteriophage lysin is characterized by high stability, wide bactericidal activity and efficacy, and safty. It is able to lyse bacteria specifically and is not susceptible to bacterial resistance. In the presence of phage, phage infecting bacteria and coding for endolysin then it lyse the bacteria, In the absence of the phage, holin assists the endolysin lysis the bacteria from external. In addition, the research progress on the treatment of Gram-positive bacteria, such as methicillin-resistant Staphylococcus aureus, Streptococcus pyogenes, and Gram-negative bacteria, such as Acinetobacter baumannii and Pseudomonas aeruginosa, was also discussed in this paper.
ABSTRACT
Treatment of bovine mastitis caused by Staphylococcus (S.) aureus is becoming very difficult due to the emergence of multidrug-resistant strains. Hence, the search for novel therapeutic alternatives has become of great importance. Consequently, bacteriophages and their endolysins have been identified as potential therapeutic alternatives to antibiotic therapy against S. aureus. In the present study, the gene encoding lysin (LysSA4) in S. aureus phage SA4 was cloned and the nucleotide sequence was determined. Sequence analysis of the recombinant clone revealed a single 802-bp open reading frame encoding a partial protein with a calculated mass of 30 kDa. Results of this analysis also indicated that the LysSA4 sequence shared a high homology with endolysin of the GH15 phage and other reported phages. The LysSA4 gene of the SA4 phage was subsequently expressed in Escherichia coli. Recombinant LysSA4 induced the lysis of host bacteria in a spot inoculation test, indicating that the protein was expressed and functionally active. Furthermore, recombinant lysin was found to have lytic activity, albeit a low level, against mastitogenic Staphylococcus isolates of bovine origin. Data from the current study can be used to develop therapeutic tools for treating diseases caused by drug-resistant S. aureus strains.
Subject(s)
Animals , Base Sequence , Cloning, Molecular , Gene Expression Regulation, Viral/physiology , Mucoproteins/genetics , Phylogeny , Polymerase Chain Reaction/methods , Recombinant Proteins , Staphylococcus Phages/genetics , Staphylococcus aureus/virologyABSTRACT
<p><b>OBJECTIVE</b>To study the effect of phage lysin on the growth of lysogens.</p><p><b>METHODS</b>Sputum specimens processed by modified Petroff's method were respectively treated with phagebiotics in combination with lysin and lysin alone. The specimens were incubated at 37 °C for 4 days. At the end of day 1, 2, 3 and day 4, the specimens were streaked on blood agar plates and incubated at 37 °C for 18-24 hours. The growth of normal flora observed after day 1 was considered as lysogens.</p><p><b>RESULTS</b>Sputum specimens treated with phagebiotics-lysin showed the growth of lysogens. When specimens treated with lysin alone, lysogen formation was avoided and normal flora was controlled.</p><p><b>CONCLUSIONS</b>Lysin may have no effect on the growth of lysogens.</p>
Subject(s)
Bacteria , Bacteriophages , Lysogeny , Microbial Viability , Mucoproteins , Metabolism , Sputum , Microbiology , Temperature , Time FactorsABSTRACT
Objective: To study the effect of phage lysin on the growth of lysogens. Methods: Sputum specimens processed by modified Petroff's method were respectively treated with phagebiotics in combination with lysin and lysin alone. The specimens were incubated at 37℃ for 4 days. At the end of day 1, 2, 3 and day 4, the specimens were streaked on blood agar plates and incubated at 37℃ for 18-24 hours. The growth of normal flora observed after day 1 was considered as lysogens.Results:When specimens treated with lysin alone, lysogen formation was avoided and normal flora was controlled. Conclusions: Lysin may have no effect on the growth of lysogens. Sputum specimens treated with phagebiotics-lysin showed the growth of lysogens.
ABSTRACT
Lysins are efficient bacteria cell wall digesting enzymes encoded by DNA bacteriophage. Gram-positive bacteriophage lysins feature similar domain structure, high lytic efficiency, synergic antibacterial effect with antibiotics, rare neutralization by antibodies, less chance of developing drug-resistant strains, et al. The past decade has seen a considerable amount of research worldwidely focused on lysin, and lysins have been used successfully in a variety of animal models to control pathogenic antibiotic resistant bacteria found on mucosal surfaces and infected tissues. The great potential of lysins as an anti-infective agent prompted this review.