Systemic immunity triggered by local plant-microbe interactions is studied as systemic acquired resistance (SAR) or induced systemic resistance (ISR) depending on the site of induction and the lifestyle of the inducing microorganism. SAR is induced by pathogens interacting with leaves, whereas ISR is induced by beneficial microbes interacting with roots. Although salicylic acid (SA) is a central component of SAR, additional signals exclusively promote systemic and not local immunity. These signals cooperate in SAR-and possibly also ISR-associated signaling networks that regulate systemic immunity. The non-SA SAR pathway is driven by pipecolic acid or its presumed bioactive derivative N-hydroxy-pipecolic acid. This pathway further regulates interplant defense propagation through volatile organic compounds that are emitted by SARinduced plants and recognized as defense cues by neighboring plants. Both SAR and ISR influence phytohormone crosstalk towards enhanced defense against pathogens, which at the same time affects the composition of the plant microbiome. This potentially leads to further changes in plant defense, plant-microbe, and plant-plant interactions. Therefore, we propose that such inter-organismic interactions could be combined in potentially highly effective plant protection strategies.
hBDs and IL-6 and IL-8, cytokines with pivotal importance in sclerotic skin diseases, are downregulated by UVA1 in the lesional skin of patients with LS. Their pathogenetic relevance with respect to clinical improvement needs further investigation.
The effects of acute and chronic ultraviolet (UV) on the morphology of human skin have been extensively studied ex vivo by means of histological investigations. However, innovative skin imaging techniques enable visualization of micromorphological structures in vivo. We aimed to perform a correlation study evaluating in vivo dose and time dependent skin changes following solar-simulated irradiation using noninvasive techniques such as optical coherence tomography (OCT) and confocal laser scanning microscopy (CLSM). The forearms of 10 healthy subjects were exposed to 1 minimal erythema dose (MED) and 3 MED of solar-simulated radiation. Noninvasive measurements were performed before and 24 h and 72 h after UV exposures. We demonstrate definite OCT and CLSM findings obtained from UV-exposed skin, including an increase in epidermal thickness (hyperproliferation, acanthosis), a reduction in dermal reflectivity (dermal edema), an increase in brightness of the basal layer (pigmentation), and an increase in vessel diameter within the dermal papillae (vasodilatation). A moderate to strong linear association between the methods employed was observed. In conclusion, noninvasive high-resolution imaging techniques such as OCT and CLSM may be promising tools for photobiological studies aimed at assessing photoadaptive and/or phototoxic processes in vivo. However, larger studies are needed to demonstrate the applicability of the findings presented in this pilot study.
Aims: Quinone compounds are electron carriers and have antimicrobial and toxic properties due to their mode of actions as electrophiles and oxidants. However, the regulatory mechanism of quinone resistance is less well understood in the pathogen Staphylococcus aureus. Results: Methylhydroquinone (MHQ) caused a thiol-specific oxidative and electrophile stress response in the S. aureus transcriptome as revealed by the induction of the PerR, QsrR, CstR, CtsR, and HrcA regulons. The SACOL2531-29 operon was most strongly upregulated by MHQ and was renamed as mhqRED operon based on its homology to the Bacillus subtilis locus. Here, we characterized the MarR-type regulator MhqR (SACOL2531) as quinone-sensing repressor of the mhqRED operon, which confers quinone and antimicrobial resistance in S. aureus. The mhqRED operon responds specifically to MHQ and less pronounced to pyocyanin and ciprofloxacin, but not to reactive oxygen species (ROS), hypochlorous acid, or aldehydes. The MhqR repressor binds specifically to a 9-9 bp inverted repeat (MhqR operator) upstream of the mhqRED operon and is inactivated by MHQ in vitro, which does not involve a thiol-based mechanism. In phenotypic assays, the mhqR deletion mutant was resistant to MHQ and quinone-like antimicrobial compounds, including pyocyanin, ciprofloxacin, norfloxacin, and rifampicin. In addition, the mhqR mutant was sensitive to sublethal ROS and 24 h post-macrophage infections but acquired an improved survival under lethal ROS stress and after long-term infections. Innovation: Our results provide a link between quinone and antimicrobial resistance via the MhqR regulon of S. aureus. Conclusion: The MhqR regulon was identified as a novel resistance mechanism towards quinone-like antimicrobials and contributes to virulence of S. aureus under long-term infections.
For the first time in Europe hundreds of rare disease (RD) experts team up to actively share and jointly analyse existing patient’s data. Solve-RD is a Horizon 2020-supported EU flagship project bringing together >300 clinicians, scientists, and patient representatives of 51 sites from 15 countries. Solve-RD is built upon a core group of four European Reference Networks (ERNs; ERN-ITHACA, ERN-RND, ERN-Euro NMD, ERN-GENTURIS) which annually see more than 270,000 RD patients with respective pathologies. The main ambition is to solve unsolved rare diseases for which a molecular cause is not yet known. This is achieved through an innovative clinical research environment that introduces novel ways to organise expertise and data. Two major approaches are being pursued (i) massive data re-analysis of >19,000 unsolved rare disease patients and (ii) novel combined -omics approaches. The minimum requirement to be eligible for the analysis activities is an inconclusive exome that can be shared with controlled access. The first preliminary data re-analysis has already diagnosed 255 cases form 8393 exomes/genome datasets. This unprecedented degree of collaboration focused on sharing of data and expertise shall identify many new disease genes and enable diagnosis of many so far undiagnosed patients from all over Europe.
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