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The human body is inhabited by around 1013 microbes composing a multicomplex system, termed microbiota, which is strongly involved in the regulation and maintenance of homeostasis. Perturbations in microbiota composition can lead to dysbiosis, which has been associated with several human pathologies. The gold-standard method to explore microbial composition is next-generation sequencing, which involves the analysis of 16S rRNA, an indicator of the presence of specific microorganisms and the principal tool used in bacterial taxonomic classification. Indeed, the development of 16S RNA sequencing allows us to explore microbial composition in several environments and human body districts and fluids, since it has been detected in “germ-free” environments such as blood, plasma, and urine of diseased and healthy subjects. Recently, prokaryotes showed to generate extracellular vesicles, which are known to be responsible for shuttling different intracellular components such as proteins and nucleic acids (including 16S molecules) by protecting their cargo from degradation. These vesicles can be found in several human biofluids and can be exploited as tools for bacterial detection and identification. In this review, we examine the complex link between circulating 16S RNA molecules and bacteria-derived vesicles.

Neurosteroids can modulate I³-aminobutyric acid type A receptor-mediated inhibitory currents. Recently, we discovered that the neurosteroids progesterone, 5α-dihydroprogesterone, allopregnanolone, and pregnanolone are reduced in the cerebrospinal fluid of patients with status epilepticus (SE). However, it is undetermined whether neurosteroids influence SE. For this reason, first we evaluated whether the inhibitor of adrenocortical steroid production trilostane (50 mg/kg) could modify the levels of neurosteroids in the hippocampus and neocortex, and we found a remarkable increase in pregnenolone, progesterone, 5α-dihydroprogesterone, and allopregnanolone levels using liquid chromatography tandem mass spectrometry. Second, we characterized the dynamics of SE in the presence of the varied neurosteroidal milieu by a single intraperitoneal kainic acid (KA; 15 mg/kg) injection in trilostane-treated rats and their controls. Convulsions started in advance in the trilostane group, already appearing 90 minutes after the KA injection. In contrast to controls, convulsions prevalently developed as generalized seizures with loss of posture in the trilostane group. However, this effect was transient, and convulsions waned 2 hours before the control group. Moreover, electrocorticographic traces of convulsions were shorter in trilostane-treated rats, especially at the 180-minute (P

International audience; 1. Diet quality may have an important effect on the regulation of oxidative statusand the immune system during an infectious disease. However, the relationshipamong intake of specific dietary molecules, an individual’s oxidative status and theoccurrence and progress of a viral disease remains almost unexplored in free‐livingorganisms.2. Here, we study a wild, long‐lived animal, the Magnificent frigatebird Fregata magnificensto investigate: (a) the differences in a number of physiological traits (biomarkersof blood oxidative status, corticosterone (CORT), immunity andinflammation) between sick and healthy nestlings; and (b) whether experimentallyincreased intake of resveratrol (a polyphenol with antioxidant and antiviral properties)affects these physiological markers during the progress of a severe viraldisease.3. Birds with visible clinical signs showed higher oxidative damage, haemolysis andhaemagglutination scores and lower antioxidant defences in comparison withbirds without clinical signs. At the end of the experiment, supplemented birdsshowed the following: (a) increased plasma haptoglobin levels and circulating antioxidantdefences; (b) reduced generation of lipid oxidative damage; and (c) negligibleto no influence on immune markers, baseline CORT levels and activity ofantioxidant enzymes.4. Our work illustrates how the availability of specific organic molecules in the dietmay constrain the individuals’ capacity to cope with viral infections in free‐livinganimals

Summary 1.There is substantial interest of evolutionary ecologists in the proximate mechanisms that modulate vocal communication. In recent times, there has been growing interest in the role of oxidative stress as a mediator of avian song expression. 2.Here we tested whether the experimental inhibition of the synthesis of a key cellular antioxidant (glutathione) reduces song rate metrics of male European starlings (Sturnus vulgaris). We measured the effect of our treatment on total song rate and on its two components, undirected and nest-box oriented song, outside the breeding season. 3.Treated males that did not own a nest-box (subordinate males likely to be of lower quality) suffered increased oxidative stress relative to untreated males, while treated males that owned a nest-box (dominant males likely to be of higher quality) did not. Treated non-owners also reduced their undirected song rate, whereas treated nest-box owners did not suffer any reduction in song rate. 4.Our results revealed that inhibition of a key cellular antioxidant results in decreased vocal communication in a social vertebrate, and that this effect is dependent on its social status (nest-box owner versus non-owner). 5.This work provides support for the hypothesis that acoustic signals may honestly convey information about the individual oxidative status and capacity to regulate the oxidative balance. Our findings raise the possibility of hitherto unexplored impacts of oxidative stress on fitness traits in social species. This article is protected by copyright. All rights reserved.