Effect of partial decapitation (hypophysectomy) on 17β-estradioI secretion by the chick embryo ovary

Ovaries of equally matched partially decapitated (hypophysectomized) and sham-operated (at 42 h of incubation) 11 1/2-day-old chick embryos, i.e. embryos as identical as possible as regards body size and other morphological features, were compared with respect to the amounts of 17 beta-estradiol secreted during a 4 h-culture period. The 17 beta-estradiol secretion rate was very significantly lower in the decapitated than in the control embryos. This result suggests that the hypophysis controls 17 beta-estradiol secretion of the ovary in the 11 1/2-day old chick embryo.     

IL-10 and Lymphotoxin-α Expression Profiles within Marginal Zone-Like B-Cell Populations Are Associated with Control of HIV-1 Disease Progression

Understanding how the immune system facilitates or controls HIV-1 disease progression has important implications for the design of effective interventions. We report that although B-cell dysregulations associated with HIV-1 disease progression are accompanied by an overall decrease in the percentage of total blood B-cells, we observe an increase in relative frequencies of cells presenting characteristics of both transitional immature and first-line marginal zone (MZ) B-cell populations, we designated as precursor MZ-like B-cells. B-cells with similar attributes have been associated with IL-10 expression and “regulatory” potential. As such, the relative frequencies of precursor MZ-like B-cells expressing IL-10 are increased in the blood of viremic HIV-1-infected individuals when compared to HIV-negative subjects. Importantly, in aviremic HIV-1 Elite-Controllers (EC), we found unaltered relative percentages of precursor MZ-like B-cells which presented normal IL-10 expression patterns. Furthermore, EC had increased relative frequencies of blood MZ-like B-cells expressing LT-α. Thus in contrast to viremic HIV-1-infected individuals, EC present MZ-like B-cell populations which IL-10 and LT-α expression profiles may favour homeostasis of immune responses and lymphoid microenvironments.     

Pro-melanin-concentrating hormone gene (PMCH) is localized on human chromosome 12q and rat chromosome 7

Melanin-concentrating hormone (MCH) is a cyclic neuropeptide that may be involved in regulation of the stress response and food intake behavior in mammals. MCH and two other putative neuropeptides, NEI and NGE, are encoded by the same precursor, designated pro-melanin-concentrating hormone (PMCH). A panel of somatic cell hybrids segregating either human or rat chromosomes was used to determine the chromosomal localization of the PMCH locus. It was assigned to human chromosome 12q and to rat chromosome 7. This is the first neuropeptide-encoding gene found in this new synteny group conserved in rat and human.     

Fluoride-Tolerant Mutants of Aspergillus niger Show Enhanced Phosphate Solubilization Capacity

P-solubilizing microorganisms are a promising alternative for a sustainable use of P against a backdrop of depletion of high-grade rock phosphates (RPs). Nevertheless, toxic elements present in RPs, such as fluorine, can negatively affect microbial solubilization. Thus, this study aimed at selecting Aspergillus niger mutants efficient at P solubilization in the presence of fluoride (F⁻). The mutants were obtained by exposition of conidia to UV light followed by screening in a medium supplemented with Ca₃(PO₄)₂ and F⁻. The mutant FS1-555 showed the highest solubilization in the presence of F⁻, releasing approximately 70% of the P contained in Ca₃(PO₄)₂, a value 1.7 times higher than that obtained for the wild type (WT). The mutant FS1-331 showed improved ability of solubilizing fluorapatites, increasing the solubilization of Araxá, Catalão, and Patos RPs by 1.7, 1.6, and 2.5 times that of the WT, respectively. These mutants also grew better in the presence of F⁻, indicating that mutagenesis allowed the acquisition of F⁻ tolerance. Higher production of oxalic acid by FS1-331 correlated with its improved capacity for RP solubilization. This mutant represents a significant improvement and possess a high potential for application in solubilization systems with fluoride-rich phosphate sources.     

Potentially Probiotic Limosilactobacillus fermentum Fruit-Derived Strains Alleviate Cardiometabolic Disorders and Gut Microbiota Impairment in Male Rats Fed a High-Fat Diet

Probiotics and Antimicrobial Proteins - High-fat diet (HFD) consumption is a risk factor for dyslipidemias, insulin resistance, and arterial hypertension linked with gut dysbiosis. Probiotic...     

How phenotypic convergence arises in experimental evolution

Evolutionary convergence is a core issue in the study of adaptive evolution, as well as a highly debated topic at present. Few studies have analyzed this issue using a “real‐time” or evolutionary trajectory approach. Do populations that are initially differentiated converge to a similar adaptive state when experiencing a common novel environment? Drosophila subobscura populations founded from different locations and years showed initial differences and variation in evolutionary rates in several traits during short‐term (～20 generations) laboratory adaptation. Here, we extend that analysis to 40 more generations to analyze (1) how differences in evolutionary dynamics among populations change between shorter and longer time spans, and (2) whether evolutionary convergence occurs after 60 generations of evolution in a common environment. We found substantial variation in longer term evolutionary trajectories and differences between short‐ and longer term evolutionary dynamics. Although we observed pervasive patterns of convergence toward the character values of long‐established populations, populations still remain differentiated for several traits at the final generations analyzed. This pattern might involve transient divergence, as we report in some cases, indicating that more generations should lead to final convergence. These findings highlight the importance of longer term studies for understanding convergent evolution.     

High Expression Levels of BLyS/BAFF by Blood Dendritic Cells and Granulocytes Are Associated with B-cell dysregulation in SIV-Infected Rhesus Macaques

Dendritic cells (DCs) modulate B-cell survival and differentiation, mainly through production of growth factors such as B lymphocyte stimulator (BLyS/BAFF). In recent longitudinal studies involving HIV-1-infected individuals with different rates of disease progression, we have shown that DCs were altered in number and phenotype in the context of HIV-1 disease progression and B-cell dysregulations were associated with increased BLyS/BAFF expression in plasma and by blood myeloid DCs (mDCs) in rapid and classic progressors but not in HIV-1-elite controllers (EC). Suggesting that the extent to which HIV-1 disease progression is controlled may be linked to BLyS/BAFF expression status and the capacity to orchestrate B-cell responses. Herein, longitudinal analyses of simian immunodeficiency virus (SIV)-infected rhesus macaques also revealed increased expression of BLyS/BAFF by blood mDCs as soon as day 8 and throughout infection. Strikingly, granulocytes presented the highest BLyS/BAFF expression profile in the blood of SIV-infected macaques. BLyS/BAFF levels were also increased in plasma and correlated with viral loads. Consequently, these SIV-infected animals had plasma hyperglobulinemia and reduced blood B-cell numbers with altered population frequencies. These data underscore that BLyS/BAFF is associated with immune dysregulation in SIV-infected rhesus macaques and suggest that BLyS/BAFF is a key regulator of immune activation that is highly conserved among primates. These findings emphasize the potential importance of this SIV-infected primate model to test whether blocking excess BLyS/BAFF has an effect on the overall inflammatory burden and immune restoration.     

Purinergic P2Y12 Receptor Activation in Eosinophils and the Schistosomal Host Response

Identifying new target molecules through which eosinophils secrete their stored proteins may reveal new therapeutic approaches for the control of eosinophilic disorders such as host immune responses to parasites. We have recently reported the expression of the purinergic P2Y12 receptor (P2Y12R) in human eosinophils; however, its functional role in this cell type and its involvement in eosinophilic inflammation remain unknown. Here, we investigated functional roles of P2Y12R in isolated human eosinophils and in a murine model of eosinophilic inflammation induced by Schistosoma mansoni (S. mansoni) infection. We found that adenosine 5’-diphosphate (ADP) induced human eosinophils to secrete eosinophil peroxidase (EPO) in a P2Y12R dependent manner. However, ADP did not interfere with human eosinophil apoptosis or chemotaxis in vitro. In vivo, C57Bl/6 mice were infected with cercariae of the Belo Horizonte strain of S. mansoni. Analyses performed 55 days post infection revealed that P2Y12R blockade reduced the granulomatous hepatic area and the eosinophilic infiltrate, collagen deposition and IL-13/IL-4 production in the liver without affecting the parasite oviposition. As found for humans, murine eosinophils also express the P2Y12R. P2Y12R inhibition increased blood eosinophilia, whereas it decreased the bone marrow eosinophil count. Our results suggest that P2Y12R has an important role in eosinophil EPO secretion and in establishing the inflammatory response in the course of a S. mansoni infection.