Antimicrobial peptides are widely distributed in nature,existing in organisms of plants,insects,and vertebrates.It has been approved that antimicrobial peptides have broad spectrum antimicrobial activities,and play a ...Antimicrobial peptides are widely distributed in nature,existing in organisms of plants,insects,and vertebrates.It has been approved that antimicrobial peptides have broad spectrum antimicrobial activities,and play a key modulatory role in the innate immune response and tumor inhibiting activity.Due to the special action mechanism,the antimicrobial peptides become a hot field of genetic engineering.In the present paper,the general properties,mechanism of action,application value,existing problems,the latest progress and the expression strategy were discussed.展开更多
OBJECTIVE Metrnl is a novel secreted protein with limited researches.In this study,we investigated metrnl tissue expression pattern in humans,and exploredthe possible role of its highest expression using animal models...OBJECTIVE Metrnl is a novel secreted protein with limited researches.In this study,we investigated metrnl tissue expression pattern in humans,and exploredthe possible role of its highest expression using animal models.METHODS We examined metrnl tissue expression pattern in a human tissue microarray containing 19types of tissues from 69 donors,and verified the highest expression in fresh human and mouse tissues.We then created an animal model of cell-specific knockout mice to study the role of metrnl.RESULTS Metrnl was the highest expressed in human gastrointestinal tract,and specifical y expressed in the intestinal epithelium.Consistently,Metrnl expression was also the highest expressed in mouse gastrointestinal tract among the detected tissues of 14 types.We developed intestinal epithelial cellspecific metrnl knockout mice with Vil in-Cre.In this animal model,metrnl levels displayed a statistically significant reduction in gut fluid,but not in blood serum.This cell specific deletion of metrnl did not affect body weight,food intake,blood glucose,colon length and histology,intestinal permeability,mucus production and mucin 2 expression under physiological conditions,but markedly reduced the expression of antimicrobial peptides,such as regenerating islet-derived 3 gamma and lactotransferrin.CONCLUSION Metrnl is rich in intestinal epithelial cells of humans and mice,mainly contributing to local gut metrnl level,and less affecting systemic circulating metrnl level.Metrnl plays a role in maintaining gut antimicrobial peptides.展开更多
Antimicrobial peptides may be regarded as a potential source of future antibiotics, and the modes of action have implicated the cationic and hydrophobic nature of their interaction with bacterial membranes. In the pre...Antimicrobial peptides may be regarded as a potential source of future antibiotics, and the modes of action have implicated the cationic and hydrophobic nature of their interaction with bacterial membranes. In the present study, a 16-residue peptide (LGR16) was developed with the aim of examining the feasibility of designing an antimicrobial peptide by segregating hydrophobic residues in the nonpolar side and positively charged residues in the polar side, based on the helical wheel projections. Antimicrobial activity, hemolytic activity, cytotoxicity against mammalian cells and bactericidal kinetics were investigated to fully evaluate the biological function of the peptide. The results showed that the peptide LGR16 had strong antimicrobial activity, and its MICs against Gram-negative and Gram-positive bacteria were 8 and 4 μg/mL, respectively. LGR16 also exhibited rapid bactericidal action and had totally eradicated the bacteria at 10 min. LGR16 showed only weak hemolysis against chicken red blood cells and cytotoxicity aginst Vero cells at its MICs, and the concentration that caused 50% hemolysis exceeded its MICs 8-fold. Overall, antimicrobial peptides can be designed by assembling hydrophobic residues in the hydrophobic side and basic residues in the opposite side. The peptide LGR16 may be developed as a prospective candidate for an antimicrobial drug.展开更多
基金Supported by National 863 Project of China (2006AA10A206)
文摘Antimicrobial peptides are widely distributed in nature,existing in organisms of plants,insects,and vertebrates.It has been approved that antimicrobial peptides have broad spectrum antimicrobial activities,and play a key modulatory role in the innate immune response and tumor inhibiting activity.Due to the special action mechanism,the antimicrobial peptides become a hot field of genetic engineering.In the present paper,the general properties,mechanism of action,application value,existing problems,the latest progress and the expression strategy were discussed.
基金The project supported by National Natural Science Foundation of China(81130061,81202572,81373414)
文摘OBJECTIVE Metrnl is a novel secreted protein with limited researches.In this study,we investigated metrnl tissue expression pattern in humans,and exploredthe possible role of its highest expression using animal models.METHODS We examined metrnl tissue expression pattern in a human tissue microarray containing 19types of tissues from 69 donors,and verified the highest expression in fresh human and mouse tissues.We then created an animal model of cell-specific knockout mice to study the role of metrnl.RESULTS Metrnl was the highest expressed in human gastrointestinal tract,and specifical y expressed in the intestinal epithelium.Consistently,Metrnl expression was also the highest expressed in mouse gastrointestinal tract among the detected tissues of 14 types.We developed intestinal epithelial cellspecific metrnl knockout mice with Vil in-Cre.In this animal model,metrnl levels displayed a statistically significant reduction in gut fluid,but not in blood serum.This cell specific deletion of metrnl did not affect body weight,food intake,blood glucose,colon length and histology,intestinal permeability,mucus production and mucin 2 expression under physiological conditions,but markedly reduced the expression of antimicrobial peptides,such as regenerating islet-derived 3 gamma and lactotransferrin.CONCLUSION Metrnl is rich in intestinal epithelial cells of humans and mice,mainly contributing to local gut metrnl level,and less affecting systemic circulating metrnl level.Metrnl plays a role in maintaining gut antimicrobial peptides.
文摘Antimicrobial peptides may be regarded as a potential source of future antibiotics, and the modes of action have implicated the cationic and hydrophobic nature of their interaction with bacterial membranes. In the present study, a 16-residue peptide (LGR16) was developed with the aim of examining the feasibility of designing an antimicrobial peptide by segregating hydrophobic residues in the nonpolar side and positively charged residues in the polar side, based on the helical wheel projections. Antimicrobial activity, hemolytic activity, cytotoxicity against mammalian cells and bactericidal kinetics were investigated to fully evaluate the biological function of the peptide. The results showed that the peptide LGR16 had strong antimicrobial activity, and its MICs against Gram-negative and Gram-positive bacteria were 8 and 4 μg/mL, respectively. LGR16 also exhibited rapid bactericidal action and had totally eradicated the bacteria at 10 min. LGR16 showed only weak hemolysis against chicken red blood cells and cytotoxicity aginst Vero cells at its MICs, and the concentration that caused 50% hemolysis exceeded its MICs 8-fold. Overall, antimicrobial peptides can be designed by assembling hydrophobic residues in the hydrophobic side and basic residues in the opposite side. The peptide LGR16 may be developed as a prospective candidate for an antimicrobial drug.
