Project description:Type I interferons were discovered as the primary antiviral cytokines and are now known to serve critical functions in host defense against bacterial pathogens. Accordingly, established mediators of interferon antiviral activity may mediate previously unrecognized antibacterial functions. RNase-L is the terminal component of an RNA decay pathway that is an important mediator of interferon-induced antiviral activity. Here we identify a novel role for RNase-L in the host antibacterial response. RNase-L-/- mice exhibited a dramatic increase in mortality following challenge with Bacillus anthracis and Escherichia coli; this increased susceptibility was due to a compromised immune response resulting in increased bacterial load. Investigation of the mechanisms of RNase-L antibacterial activity indicated that RNase-L is required for the optimal induction of proinflammatory cytokines that play essential roles in host defense from bacterial pathogens. RNase-L also regulated the expression of the endolysosomal protease, cathepsin-E, and endosome-associated activities, that function to eliminate internalized bacteria and may contribute to RNase-L antimicrobial action. Our results reveal a unique role for RNase-L in the antibacterial response that is mediated through multiple mechanisms. As a regulator of fundamental components of the innate immune response, RNase-L represents a viable therapeutic target to augment host defense against diverse microbial pathogens. two strains: wildtype and knockout, three time points: untreated, 2hours, and 8hours. three replication for each group. Totally 18 samples.
Project description:Type I interferons were discovered as the primary antiviral cytokines and are now known to serve critical functions in host defense against bacterial pathogens. Accordingly, established mediators of interferon antiviral activity may mediate previously unrecognized antibacterial functions. RNase-L is the terminal component of an RNA decay pathway that is an important mediator of interferon-induced antiviral activity. Here we identify a novel role for RNase-L in the host antibacterial response. RNase-L-/- mice exhibited a dramatic increase in mortality following challenge with Bacillus anthracis and Escherichia coli; this increased susceptibility was due to a compromised immune response resulting in increased bacterial load. Investigation of the mechanisms of RNase-L antibacterial activity indicated that RNase-L is required for the optimal induction of proinflammatory cytokines that play essential roles in host defense from bacterial pathogens. RNase-L also regulated the expression of the endolysosomal protease, cathepsin-E, and endosome-associated activities, that function to eliminate internalized bacteria and may contribute to RNase-L antimicrobial action. Our results reveal a unique role for RNase-L in the antibacterial response that is mediated through multiple mechanisms. As a regulator of fundamental components of the innate immune response, RNase-L represents a viable therapeutic target to augment host defense against diverse microbial pathogens.
Project description:The aqueous extract of yerba mate, a South American tea beverage made from Ilex paraguariensis leaves, has demonstrated bactericidal and inhibitory activity against bacterial pathogens, including methicillin-resistant Staphylococcus aureus (MRSA). The gas chromatography-mass spectrometry (GC-MS) analysis of two unique fractions of yerba mate aqueous extract revealed 8 identifiable small molecules in those fractions with antimicrobial activity. For a more comprehensive analysis, a data analysis pipeline was assembled to prioritize compounds for antimicrobial testing against both MRSA and methicillin-sensitive S. aureus using forty-two unique fractions of the tea extract that were generated in duplicate, assayed for activity, and analyzed with GC-MS. As validation of our automated analysis, we checked our predicted active compounds for activity in literature references and with used authentic standards to test for antimicrobial activity. 3,4-dihydroxybenzaldehyde showed the most antibacterial activity against MRSA at low concentrations in our bioassays. In addition, quinic acid and quercetin were identified using random forests analysis and 5-hydroxy pipecolic acid was identified using linear discriminant analysis. We additionally also generated a ranked list of unidentified compounds that may contribute to the antimicrobial activity of yerba mate against MRSA. Here we utilized GC-MS data to implement an automated analysis that resulted in a ranked list of compounds that likely contribute to the antimicrobial activity of aqueous yerba mate extract against MRSA.
2015-03-19 | MTBLS170 | MetaboLights
Project description:Antibacterial activity of baicalin against MRSA
Project description:To predict the different genes, this study compared the gene expression level among the control group, the model group and the treatment groups. In this present study, 20 Wistar rats, weighting 160-180g and as the sex evenly, were randomly divided into five groups: normal control group, model control group , Haizao Yuhu decoction group, Haizao Yuhu decotion lacking Sargassum fusiforme (DL-S) group, and Haizao Yuhu decotion lacking Radix Glycyrrhiza (DL-G) group. Except the rats in control and model groups, the three other groups, which were established as goiter model, were administered appropriate medication at the dose of 1mL/100g for 28 consecutive days. After all animals sacrificed, thyroids were removed and then put in Trizol for microarray experiments.
Project description:The effectiveness of antibacterial agents is strongly influenced by its antibacterial mechanism, which, in turn, is dependent on the agent’s topological structure. In addition to oxidative stress (especially caused by reactive oxygen species), known to be a key mechanism for 2D phosphorene structures, physical penetration of bacterial cell membranes is predicted for violet phosphorene nanosheets. In this study, we demonstrate that violet phosphorus (VP) and its exfoliated product, violet phosphorene nanosheets (VPNS), have superior antibacterial capability against pathogens.A series of antibacterial tests and theoretical calculations show that VPNS can inactivate >99.9% of two common pathogens (Escherichia coli and Staphylococcus aureus) and >99% of two “superbugs” (i.e., antibiotic-resistant bacteria, Escherichia coli pUC19 and methicillin-resistant Staphylococcus aureus) via oxidative stress combined with cell membrane penetration by VPNS Moreover, VPNS have higher antibacterial activity than black phosphorene nanosheets in vitro and in vivo. We believe VPNS as special rigidly structured nanoagents have great potential for eradicating pathogens.