Seasonal changes in gene expression of steroidogenic enzymes,androgen and estrogen receptors in frog testis

The anuran amphibian Pelophylax esculentus shows an annual cycle of sexual steroid production and spermatogenesis. To more thoroughly comprehend the steroidogenic pathways that govern the seasonal reproductive cycle, we investigated the mRNA expression of key enzymes involved in the androgenic and oestrogenic biosynthesis pathways in the testis of frogs taken in the reproductive and postreproductive period. Furthermore, we also analysed androgen and oestrogen levels and their own receptor gene expressions. Our findings showed that during the reproductive period, 3β‐hydroxysteroid dehydrogenase, 17β‐hydroxysteroid dehydrogenase and 5α‐reductase mRNA levels were higher than those during the postreproductive period. High testosterone and 5α‐dihydrotestosterone titres as well as the expression levels of androgen receptors in the reproductive testis strongly confirmed that the androgenic pathway is necessary for spermatogenesis activation. Conversely, during the postreproductive period, the highest P450 aromatase, estrogen receptor α and β mRNA levels, paralleling with oestradiol titres, indicated that the oestrogenic pathway is essential for the interruption of the reproductive processes. Our findings demonstrated, for the first time in amphibians, that testicular endocrine cyclic activity could be modulated by the up‐regulation of key steroidogenic enzyme gene expressions. This in turn determines the activation of the androgenic pathway in reproductive phase and the oestrogenic one in postreproductive phase.     

Innovative biomarkers in psychiatric disorders: a major clinical challenge in psychiatry

Introduction: Currently, the diagnosis of psychiatric illnesses is based upon DSM-5 criteria. Although endophenotype-specificity for a particular disorder is discussed, the identification of objective biomarkers is ongoing for aiding diagnosis, prognosis, or clinical response to treatment. We need to improve the understanding of the biological abnormalities in psychiatric illnesses across conventional diagnostic boundaries. The present review investigates the innovative post-genomic knowledge used for psychiatric illness diagnostics and treatment response, with a particular focus on proteomics.

Areas covered: This review underlines the contribution that psychiatric innovative biomarkers have reached in relation to diagnosis and theragnosis of psychiatric illnesses. Furthermore, it encompasses a reliable representation of their involvement in disease through proteomics, metabolomics/pharmacometabolomics and lipidomics techniques, including the possible role that gut microbiota and CYP2D6 polimorphisms may play in psychiatric illnesses.

Expert opinion: Etiologic heterogeneity, variable expressivity, and epigenetics may impact clinical manifestations, making it difficult for a single measurement to be pathognomonic for multifaceted psychiatric disorders. Academic, industry, or government’s partnerships may successfully identify and validate new biomarkers so that unfailing clinical tests can be developed. Proteomics, metabolomics, and lipidomics techniques are considered to be helpful tools beyond neuroimaging and neuropsychology for the phenotypic characterization of brain diseases.     

B cell selection and susceptibility to autoimmunity

Autoreactive B cells arise routinely as part of the naive B cell repertoire. The immune system employs several mechanisms in an attempt to silence these autoreactive cells before they achieve immunocompetence. The BCR plays a central role in B cell development, activation, survival, and apoptosis, and thus is a critical component of the regulation of both protective and autoreactive B cells. The strength of signal mediated by the BCR is determined by numerous factors, both B cell intrinsic and B cell extrinsic. Perturbations in the molecules that regulate the BCR signal strength or that activate pathways that engage in cross talk with the BCR-mediated signaling pathways can lead to the aberrant survival and activation of autoreactive B cells. In this review, we will discuss the some newly identified genetic loci and factors that modulate the BCR signal transduction pathway and, therefore, the regulation of autoreactive B cells. We will also provide evidence for a model of autoreactivity in which a reduction in the strength of the BCR signal allows the survival and the modulation of a naive B cell repertoire replete with autoreactivity.     

Asymmetric binding of the high-affinity Q(H)(*)(-) ubisemiquinone in quinol oxidase (bo3) from Escherichia coli studied by multifrequency electron paramagnetic resonance spectroscopy

Ubiquinone-2 (UQ-2) selectively labeled with (13)C (I =(1)/(2)) at either the position 1- or the 4-carbonyl carbon is incorporated into the ubiquinol oxidase bo(3) from Escherichia coli in which the native quinone (UQ-8) has been previously removed. The resulting stabilized anion radical in the high-affinity quinone-binding site (Q(H)(*)(-)) is investigated using multifrequency (9, 34, and 94 GHz) electron paramagnetic resonance (EPR) spectroscopy. The corresponding spectra reveal dramatic differences in (13)C hyperfine couplings indicating a strongly asymmetric spin density distribution over the quinone headgroup. By comparison with previous results on labeled ubisemiquinones in proteins as well as in organic solvents, it is concluded that Q(H)(*)(-) is most probably bound to the protein via a one-sided hydrogen bond or a strongly asymmetric hydrogen-bonding network. This observation is discussed with regard to the function of Q(H) in the enzyme and contrasted with the information available on other protein-bound semiquinone radicals.     

Probing protein aggregation by time-resolved fluorescence during beta-lactoglobulin crystal growth

We have used the fluorescence anisotropy (FA) decay of retinol bound to bovine beta-lactoglobulin to monitor the time evolution of protein aggregation during the early stages of crystal growth. With this approach we have followed the formation of aggregates at different concentrations of ammonium sulfate, the precipitant used for crystallization. The average aggregation number is found to depend on precipitant concentration, and to be restricted to small numbers ranging from 2 to 5, also in the presence of visible growing crystals. The effect of particle distribution and of low probe-to-protein saturation on the FA response is also discussed in detail.     

Effects of extremely low frequency (50 Hz) magnetic field on morphological and biochemical properties of human keratinocytes

We investigated the effects on human keratinocytes (HaCaT) of exposure to a sinusoidal magnetic field of 2 mT (50 Hz). These cells are a good model for studying interaction of nonionising radiation, because they are not shielded from fields in vivo and also because they are resistant to both mechanical and thermal stimuli. We performed scanning microscopy which showed modification in shape and morphology in exposed cells. This modification is related to differential actin distribution as revealed by phalloidin fluorescence analysis. Moreover, the exposed cells show increased clonogenic capacity, as well as increased cellular growth as showed by clonogenicity assays and growth curves. Indirect immunofluorescence analysis using a fluorescent antibody against involucrin and beta4 integrin, which are respectively differentiation and adhesion markers, revealed an increase of involucrin expression and segregation of beta4 integrin in the cell membrane in cells exposed to 50 Hz; a higher percentage of the exposed cells shows a modified pattern of adhesion and differentiation markers. We also present evidence that exposure of HaCaT cells can interfere with protein kinase activity. Our observations confirm the hypothesis that electromagnetic fields at 50 Hz may modify cell membrane morphology and interfere with initiation of the signal cascade pathway and cellular adhesion.