chlorophyll-a and Bacterial-Infections

A pyropheophorbide-α-based building block (Ppa-PLGVRG-Van) can be used to construct self-aggregated superstructures in vivo for highly specific and sensitive diagnosis of bacterial infection by noninvasive photoacoustic tomography. This in vivo supramolecular chemistry approach opens a new avenue for efficient, rapid, and early-stage disease diagnosis with high sensitivity and specificity.

Topics: Animals; Bacterial Infections; Chlorophyll; Contrast Media; Disease Models, Animal; Escherichia coli; Gelatinases; Mice; Models, Biological; Molecular Structure; Myositis; Nanostructures; Phantoms, Imaging; Photoacoustic Techniques; Proteus vulgaris; Staphylococcus aureus; Staphylococcus epidermidis; Tomography; Vancomycin; Water

The Arabidopsis thaliana chloroplast protein ACCELERATED CELL DEATH2 (ACD2) modulates the amount of programmed cell death (PCD) triggered by Pseudomonas syringae and protoporphyrin IX (PPIX) treatment. In vitro, ACD2 can reduce red chlorophyll catabolite, a chlorophyll derivative. We find that ACD2 shields root protoplasts that lack chlorophyll from light- and PPIX-induced PCD. Thus, chlorophyll catabolism is not obligatory for ACD2 anti-PCD function. Upon P. syringae infection, ACD2 levels and localization change in cells undergoing PCD and in their close neighbors. Thus, ACD2 shifts from being largely in chloroplasts to partitioning to chloroplasts, mitochondria, and, to a small extent, cytosol. ACD2 protects cells from PCD that requires the early mitochondrial oxidative burst. Later, the chloroplasts of dying cells generate NO, which only slightly affects cell viability. Finally, the mitochondria in dying cells have dramatically altered movements and cellular distribution. Overproduction of both ACD2 (localized to mitochondria and chloroplasts) and ascorbate peroxidase (localized to chloroplasts) greatly reduces P. syringae-induced PCD, suggesting a pro-PCD role for mitochondrial and chloroplast events. During infection, ACD2 may bind to and/or reduce PCD-inducing porphyrin-related molecules in mitochondria and possibly chloroplasts that generate reactive oxygen species, cause altered organelle behavior, and activate a cascade of PCD-inducing events.

Topics: Apoptosis; Apoptosis Regulatory Proteins; Arabidopsis; Arabidopsis Proteins; Bacterial Infections; Chlorophyll; Chloroplasts; Gene Expression; Herbicides; Hydrogen Peroxide; Light; Mitochondria; Molecular Sequence Data; Nitric Oxide; Oxidoreductases; Phenotype; Plant Diseases; Plant Leaves; Plant Roots; Protein Transport; Protoporphyrins; Pseudomonas syringae; Virulence

Topics: Aerobiosis; Amino Acids; Anaerobiosis; Bacterial Infections; Bacterial Proteins; Cell Membrane; Chlorophyll; Chromatography, Thin Layer; Electrophoresis; Electrophoresis, Polyacrylamide Gel; Hexosamines; Microscopy, Electron; Molecular Weight; Peptides; Phospholipids; Phosphorus Isotopes; Protein Binding; Protein Hydrolysates; Rhodobacter sphaeroides; Rhodopseudomonas; RNA, Bacterial; Sodium Dodecyl Sulfate; Trypsin