Dangerous liaisons for pubertal maturation: the impact of alcohol consumption and obesity on the timing of puberty.

Acquisition of reproductive maturity involves one of the most important series of developmental events in an organism's life. The beginning of adolescence is marked by the onset of puberty. Puberty is the continuum of physical changes through which an infantile body matures into an adult capable of reproduction. This is a period of increased brain plasticity, where processes of re-wiring, neuronal proliferation, and pruning are enhanced. The initiation of mammalian puberty requires an increased pulsatile release of gonadotropin-releasing hormone from the hypothalamus. Puberty is regulated by neuroendocrine, genetic, and epigenetic factors. The maturation and function of the reproductive axis are highly sensitive to the energy status of the organism and sophisticated mechanisms exist to inhibit the axis in unfavorable energetic or metabolic conditions.In this review, we will focus on the impact of alcohol and obesity on reproductive outcomes, with emphasis on their effects on the timing of puberty. In the case of obesity, conflictive data are found, and while in females the association of overnutrition with advanced onset of puberty is consistent, in males, discrepant results have been reported. Concerning alcohol exposure, compelling evidence has documented a delay in the onset of puberty. We will present here data from both clinical studies and research involving preclinical models, which do not only delineate the impact of these conditions on the timing of puberty and potential underlying mechanisms, but that may help to define better strategies for the rational management of puberty disorders, especially of metabolic origin.

Chiral Amplification in Nature: Studying Cell-Extracted Chiral Carotenoid Microcrystals via the Resonance Raman Optical Activity of Model Systems.

Carotenoid microcrystals, extracted from cells of carrot roots and consisting of 95 % of achiral ß-carotene, exhibit a very intense chiroptical (ECD and ROA) signal. The preferential chirality of crystalline aggregates that consist mostly of achiral building blocks is a newly observed phenomenon in nature, and may be related to asymmetric information transfer from the chiral seeds (small amount of α-carotene or lutein) present in carrot cells. To confirm this hypothesis, we synthesized several model aggregates from various achiral and chiral carotenoids. Because of the sergeant-and-soldier behavior, a small number of chiral sergeants (α-carotene or astaxanthin) force the achiral soldier molecules (ß- or 11,11'-[D2 ]-ß-carotene) to jointly form supramolecular assemblies of induced chirality. The chiral amplification observed in these model systems confirmed that chiral microcrystals appearing in nature might consist predominantly of achiral building blocks and their supramolecular chirality might result from the co-crystallization of chiral and achiral analogues.

In vitro virulence characteristics of rare serovars of Salmonella enterica isolated from sand lizards (Lacerta agilis L.).

The aim of this study was to estimate virulence potential of Salmonella enterica strains colonizing the gut of free-living sand lizards (Lacerta agilis L.). The strains belonged to three Salmonella serovars: Abony, Schleissheim, and Telhashomer. Adhesion and invasion abilities of the strains were determined in quantitative assays using the gentamicin protection method. Induction of apoptosis was assessed using HeLa cell monolayers. PCR assays were used for detection of 26 virulence genes localised within mobile elements: pathogenicity islands, virulence plasmids, and prophage sequences. In vitro studies revealed that all strains had adhesion and invasion abilities to human epithelial cells. The isolates were cytotoxic and induced apoptosis of the cells. The serovars differed in the number of virulence-associated genes: up to 18 genes were present in Salmonella Schleissheim, 17 in Salmonella Abony, whereas as few as six genes were found in Salmonella Telhashomer. Generally, Salmonella Abony and Salmonella Schleissheim did not differ much in gene content connected with the presence SPI-1 to -5. All of the strains lacked genes localised within bacteriophages and plasmids. The presence of virulence-associated genes and in vitro pathogenicity assays suggest that Salmonella sp. strains originating from autochthonous, free-living lizards can potentially infect and cause disease in humans.

Two weeks of moderate intensity locomotor training increased corticosterone concentrations but did not alter the number of adropin-immunoreactive cells in the hippocampus of diabetic type 2 and control rats.

Adropin (ADR) plays a role in metabolism regulation and its alterations in obesity and diabetes have been found. Treatment with ADR was beneficial in metabolic diseases, and physical exercise increased ADR concentrations in obese patients. However, data on the distribution of ADR in the brain are sparse. The role of metabolic status and physical exercise on its expression in the brain is undiscovered. We hypothesized that diabetes type 2 (DM2) and/or exercise will alter number of ADR-immunoractive (-ir) cells in the rat brain. Animals were divided into groups: diabetes type 2 (receiving high-fat diet and injections of streptozotocin) and control (fed laboratory chow diet; C). Rats were further divided into: running group (2 weeks of forced exercise on a treadmill) and non-running group. Body mass, metabolic and hormonal profiles were assessed. Immunohistochemistry was run to study ADR-ir cells in the brain. We found that: 1) in DM2 animals, running decreased insulin and increased glucose concentrations; 2) in C rats, running decreased insulin concentrations and had no effect on glucose concentration in blood; 3) running increased corticosterone (CORT) concentrations in DM2 and C rats; 4) ADR-ir cells were detected in the hippocampus and ADR-ir fibers in the arcuate nucleus of the hypothalamus, which is a novel location; 5) metabolic status and running, however, did not change number of these cells. We concluded that 2 weeks of forced moderate intensity locomotor training induced stress response present as increased concentration of CORT and did not influence number of ADR-ir cells in the brain.

Effects of short-term exposure to high-fat diet on histology of male and female gonads in rats.

Obesity, which reaches an epidemic, is characterized by alterations in metabolic and hormonal profiles. Moreover, uncontrolled obesity may lead to development of diabetes type 2, which accounts for about 90% of all diabetic cases. In obesity, besides changes in metabolism, numerous co-morbidities are reported, e.g. disruptions of reproductive functions. Additionally, sex differences in development of this disease occur. We hypothesized that short-term exposure to high-fat diet (HFD; containing 50% of total energy from fat) would alter histology of testes and ovaries, and thus contribute to reproductive disruptions in male and female rats. Adult rats were fed ad libitum with HFD for 6-7 weeks and its effects on histology of testes and ovaries (n = 4/sex and treatment group) were studied using hematoxylin-eosin staining followed by microscopic analysis and compared to control (laboratory chow fed) group. We have found that in male rats fed with HFD there were: 1) decrease in diameter of seminiferous tubules due to smaller luminar diameter, and no change in epithelium height; 2) decrease in number of Sertoli cells; 3) no changes in number of spermatogonia and in percentage of semen in seminiferous tubules. In female rats exposed to HFD we have seen: 1) decrease in diameters of corpora lutea; 2) decrease in diameter of ovarian follicles types 7 and 8, but no changes in their number; 3) no changes in number of early primary follicles, primary follicles, and secondary follicles. We concluded that relatively short-term exposure to HFD in rats leads to changes in histology of both testes and ovaries, thus affecting reproductive functions.

Effects of Ovariectomy and Sex Hormone Replacement on Numbers of Kisspeptin-, Neurokinin B- and Dynorphin A-immunoreactive Neurons in the Arcuate Nucleus of the Hypothalamus in Obese and Diabetic Rats.

KNDy neurons co-expressing kisspeptin (KP), neurokinin B (NKB) and dynorphin A (DYN A) in the arcuate nucleus of the hypothalamus (ARC) are key regulators of reproduction. Their activity is influenced by metabolic and hormonal signals. Previously, we have shown that orchidectomy alters the KP-, NKB-, and DYN A-immunoreactivity in the high-fat diet-induced (HFD) obesity and diabetes type 2 (DM2) models. Considering the potential sex difference in the response of KNDy neurons, we have hypothesized that ovariectomy (OVX) and post-ovariectomy replacement with estradiol (OVX+E2) or estradiol and progesterone (OVX+E2+P4) will also affect these neurons in HFD and DM2 females. Thus, each of these treatment protocols were employed for control, HFD, and DM2 groups of rats leading to nine experimental conditions within which we have determined the number of KP-, NKB-, or DYN-immunoreactive (-ir) neurons and assessed the metabolic and hormonal profiles of the animals. Accordingly: (1) no effects of group and surgery were observed on the number of KP-ir neurons; (2) the overall number of NKB-ir neurons was higher in the OVX+E2+P4 and OVX+E2 animals compared to OVX; (3) overall, the number of DYN A-ir neurons was higher in DM2 vs. control group, and surgery had an effect on the number of DYN A-ir neurons; (4) the metabolic and hormonal profiles were altered in HFD and DM2 animals compared to controls. Current data together with our previously published results indicate sex-specific differences in the response of KNDy neurons to DM2.

Activity of dalbavancin against gram-positive cocci isolated from skin and soft tissue infections in Poland.

A total of 368 Gram-positive cocci from ABSSI were included in the study. S. aureus and S. pyogenes were susceptible to dalbavancin with MIC50 0.016 mg/L and MIC90 0.032 mg/L for MSSA and MIC50 0.032 mg/L and MIC90 0.047 mg/L for MRSA; MICs for S. pyogenes were ≤0.002-0.008 mg/L; for E. faecalis and E. faecium, ranging 0.016-0.12 mg/L and 0.012-≥32 mg/L, respectively; MICs for VRE were 0.032-0.125 mg/L.

Diabetes Type 2 and Kisspeptin: Central and Peripheral Sex-Specific Actions.

Kisspeptin (KP) plays a major role in the regulation of reproduction governed by the hypothalamic-pituitary-gonadal (HPG) axis. However, recent findings suggest that the KP system is present not only centrally (at the level of the hypothalamus), but also in the peripheral organs crucial for the control of metabolism. The KP system is sexually differentiated in the hypothalamus, and it is of particular interest to study whether sex-specific responses to type 2 diabetes (DM2) exist centrally and peripherally. As collection of data is limited in humans, animal models of DM2 are useful to understand crosstalk between metabolism and reproduction. Sex-specific variations in the KP system reported in animals suggest a need for the development of gender specific therapeutic strategies to treat DM2.

Raman Optical Activity and Raman spectroscopy of carbohydrates in solution.

This comprehensive study on selected 14 carbohydrates in water solution is an extension of previously published one focused only on solid state analysis. Here, Raman spectroscopy was used as a dedicated method for analysis of carbohydrates in solution, both using a normal effect (RS) and its chiral analogue: Raman Optical Activity spectroscopy (ROA). The compounds were selected as biologically important and representative of all groups: monosaccharides, disaccharides, trisaccharides, cyclodextrines and polysaccharides. RS and ROA spectra are presented together with an expanded discussion on various structures and conformations of studied carbohydrates in the solution taking into account particular regions, i.e. (1) low wavenumber region (250-600 cm-1), (2) anomeric region (600-950 cm-1), (3) fingerprint region (950-1200 cm-1) and (4) CH2and COH deformations region (1200-1500 cm-1). So, the following information can be obtained about: (1) the absolute configuration of the anomeric centre; (2) the configuration of the anomeric centre and the orientation of the anomeric hydroxyl group; (3) the ring structures and the relative orientation of substituents and (4) the conformation of the exocyclic CH2OH (4), respectively. Raman spectroscopy and Raman Optical Activity were shown as unique tools to study complex structures of carbohydrates.

Contrasting requirements during disease evolution identify EZH2 as a therapeutic target in AML.

Epigenetic regulators, such as EZH2, are frequently mutated in cancer, and loss-of-function EZH2 mutations are common in myeloid malignancies. We have examined the importance of cellular context for Ezh2 loss during the evolution of acute myeloid leukemia (AML), where we observed stage-specific and diametrically opposite functions for Ezh2 at the early and late stages of disease. During disease maintenance, WT Ezh2 exerts an oncogenic function that may be therapeutically targeted. In contrast, Ezh2 acts as a tumor suppressor during AML induction. Transcriptional analysis explains this apparent paradox, demonstrating that loss of Ezh2 derepresses different expression programs during disease induction and maintenance. During disease induction, Ezh2 loss derepresses a subset of bivalent promoters that resolve toward gene activation, inducing a feto-oncogenic program that includes genes such as Plag1, whose overexpression phenocopies Ezh2 loss to accelerate AML induction in mouse models. Our data highlight the importance of cellular context and disease phase for the function of Ezh2 and its potential therapeutic implications.

Kisspeptin and Metabolism: The Brain and Beyond.

Apart from the well-established role of kisspeptin (Kp) in the regulation of reproductive functions, recent data described its action in the control of metabolism. Of particular interest for the review is the population of Kp neurons localized in the arcuate nucleus (ARC) of the hypothalamus, the site of the brain where reproductive and metabolic cross talk occurs. However, within the hypothalamus Kp does not work alone, but rather interacts with other neuropeptides, e.g., neurokinin B, dynorphin A, proopiomelanocortin, the cocaine- and amphetamine-regulated transcript, agouti-related peptide, and neuropeptide Y. Beyond the brain, Kp is expressed in peripheral tissues involved in metabolic functions. In this review, we will mainly focus on the local action of this peptide in peripheral organs such as the pancreas, liver, and the adipose tissue. We will concentrate on dysregulation of the Kp system in cases of metabolic imbalance, e.g., obesity and diabetes. Importantly, these patients besides metabolic health problems often suffer from disruptions of the reproductive system, manifested by abnormalities in menstrual cycles, premature child birth, miscarriages in women, decreased testosterone levels and spermatogenesis in men, hypogonadism, and infertility. We will review the evidence from animal models and clinical data indicating that Kp could serve as a promising agent with clinical applications in regulation of reproductive problems in individuals with obesity and diabetes. Finally, emerging data indicate a role of Kp in regulation of insulin secretion, potentially leading to development of further therapeutic uses of this peptide to treat metabolic problems in patients with these lifestyle diseases.

UTX-mediated enhancer and chromatin remodeling suppresses myeloid leukemogenesis through noncatalytic inverse regulation of ETS and GATA programs.

The histone H3 Lys27-specific demethylase UTX (or KDM6A) is targeted by loss-of-function mutations in multiple cancers. Here, we demonstrate that UTX suppresses myeloid leukemogenesis through noncatalytic functions, a property shared with its catalytically inactive Y-chromosome paralog, UTY (or KDM6C). In keeping with this, we demonstrate concomitant loss/mutation of KDM6A (UTX) and UTY in multiple human cancers. Mechanistically, global genomic profiling showed only minor changes in H3K27me3 but significant and bidirectional alterations in H3K27ac and chromatin accessibility; a predominant loss of H3K4me1 modifications; alterations in ETS and GATA-factor binding; and altered gene expression after Utx loss. By integrating proteomic and genomic analyses, we link these changes to UTX regulation of ATP-dependent chromatin remodeling, coordination of the COMPASS complex and enhanced pioneering activity of ETS factors during evolution to AML. Collectively, our findings identify a dual role for UTX in suppressing acute myeloid leukemia via repression of oncogenic ETS and upregulation of tumor-suppressive GATA programs.

SRPK1 maintains acute myeloid leukemia through effects on isoform usage of epigenetic regulators including BRD4.

We recently identified the splicing kinase gene SRPK1 as a genetic vulnerability of acute myeloid leukemia (AML). Here, we show that genetic or pharmacological inhibition of SRPK1 leads to cell cycle arrest, leukemic cell differentiation and prolonged survival of mice transplanted with MLL-rearranged AML. RNA-seq analysis demonstrates that SRPK1 inhibition leads to altered isoform levels of many genes including several with established roles in leukemogenesis such as MYB, BRD4 and MED24. We focus on BRD4 as its main isoforms have distinct molecular properties and find that SRPK1 inhibition produces a significant switch from the short to the long isoform at the mRNA and protein levels. This was associated with BRD4 eviction from genomic loci involved in leukemogenesis including BCL2 and MYC. We go on to show that this switch mediates at least part of the anti-leukemic effects of SRPK1 inhibition. Our findings reveal that SRPK1 represents a plausible new therapeutic target against AML.

Aggregation-Induced Resonance Raman Optical Activity (AIRROA) and Time-Dependent Helicity Switching of Astaxanthin Supramolecular Assemblies.

New methods for enhancing the Raman optical activity (ROA) signal are desirable due to the low efficiency of ROA, demanding otherwise high sample concentrations, high laser powers, and/or long acquisition times. Previously, we have demonstrated a new phenomenon, aggregation-induced resonance ROA (AIRROA), that produces significant enhancement of the ROA signal provided that the excitation wavelength coincides with the absorption of the measured species and that the electronic circular dichroism (ECD) signal in the range of this absorption is nonzero. In this work, analyzing three very different supramolecular astaxanthin aggregates (H1, H2, and J), we confirm the phenomenon and demonstrate that aggregation itself is not enough to enhance the ROA signal and that the above-mentioned conditions are necessary for induction of the resonance ROA effect. Additionally, by analyzing the changes in the ECD spectra of the H1 assembly, we demonstrate that the supramolecular helicity sign switches with time, which is dependent on the prevalence of kinetic or thermodynamic stabilization of the obtained aggregates.

Aggregation-Induced Resonance Raman Optical Activity (AIRROA): A New Mechanism for Chirality Enhancement.

Raman optical activity (ROA) spectroscopy is hampered by low sensitivity, with limited possibilities for enhancing the signal. In the present study, we report a new mechanism whereby chirality is enhanced using the resonance resulting from supramolecular aggregation. We have named this mechanism aggregation-induced resonance Raman optical activity (AIRROA). As an example, we study J-aggregates of astaxanthin (AXT), which show strong absorption of circularly polarized light in the range of ROA excitation. The implications of aggregation-induced signal enhancement for chiroptical spectroscopy are discussed.

Distribution pattern and number of ticks on lizards.

The success of ectoparasites depends primarily on the site of attachment and body condition of their hosts. Ticks usually tend to aggregate on vertebrate hosts in specific areas, but the distribution pattern may depend on host body size and condition, sex, life stage or skin morphology. Here, we studied the distribution of ticks on lizards and tested the following hypothesis: occurrence or high abundance of ticks is confined with body parts with smaller scales and larger interscalar length because such sites should provide ticks with superior attachment conditions. This study was performed in field conditions in central Poland in 2008-2011. In total, 500 lizards (Lacerta agilis) were caught and 839 ticks (Ixodes ricinus, larvae and nymphs) were collected from them. Using generalised linear mixed models, we found that the ticks were most abundant on forelimbs and their axillae, with 90% of ticks attached there. This part of the lizard body and the region behind the hindlimb were covered by the smallest scales with relatively wide gaps between them. This does not fully support our hypothesis that ticks prefer locations with easy access to skin between scales, because it does not explain why so few ticks were in the hindlimb area. We found that the abundance of ticks was positively correlated with lizard body size index (snout-vent length). Tick abundance was also higher in male and mature lizards than in female and young individuals. Autotomy had no effect on tick abundance. We found no correlation between tick size and lizard morphology, sex, autotomy and body size index. The probability of occurrence of dead ticks was positively linked with the total number of ticks on the lizard but there was no relationship between dead tick presence and lizard size, sex or age. Thus lizard body size and sex are the major factors affecting the abundance of ticks, and these parasites are distributed nearly exclusively on the host's forelimbs and their axillae.