Stress causes tissue-specific changes in the sialyltransferase activity

Numerous pathological conditions are associated with specific changes in glycosylation. Recent studies clearly demonstrated a link between stress and the development and course of many diseases. Biochemical mechanisms that link stress and diseases are still not fully understood, but there are some indications that changes in glycosylation are involved in this process. Influence of acute and chronic psychological stress on protein sialylation as well as the activity of sialyltransferases, enzymes that synthesize sialoglycoproteins, has been studied on Fischer rats. Liver, spleen, kidney, skeletal muscle, heart, adrenal gland, serum, cerebellum, hippocampus, medulla oblongata and cortex have been analyzed. Statistically significant tissue- and type of stress-specific changes in total sialyltransferase (ST) activity were observed. Acute stress resulted in 39% increase of ST activity in liver and spleen, while at the same time there was 43% decrease in ST activity in cerebellum. In chronic stress, ST activity increased in spleen (93%) and decreased in liver (17%), cerebellum (38%) and hippocampus (64%). Western-blot analysis using Maackia amurensis and Sambucus nigra lectins did not reveal any difference in protein sialylation. The results of serum corticosterone analysis indicate that showed increase in acute stress and decrease in chronic stress are in good accordance with the hypothesis that corticosterone has a role in the regulation of liver ST activity.     

Recombinant protein folding and misfolding in Escherichia coli

The past 20 years have seen enormous progress in the understanding of the mechanisms used by the enteric bacterium Escherichia coli to promote protein folding, support protein translocation and handle protein misfolding. Insights from these studies have been exploited to tackle the problems of inclusion body formation, proteolytic degradation and disulfide bond generation that have long impeded the production of complex heterologous proteins in a properly folded and biologically active form. The application of this information to industrial processes, together with emerging strategies for creating designer folding modulators and performing glycosylation all but guarantee that E. coli will remain an important host for the production of both commodity and high value added proteins.     

Alternative techniques to study characters of the genitalia in Lepidoptera

The present note aims to describe two alternative methods for observing genitalia in Lepidoptera. The first one provides means to examine both male and female genitalia without spoiling the scales of the abdomen, preserving it attached to the thorax and aesthetically similar to an unexamined specimen. The second one provides ways of observing certain characters on the male genitalia in a non-destructive way, and does not depend on time-consuming removing and dissection of the abdomen. It is expected that the presented techniques will help on morphological studies and on identifying similar species which consistently differ in genitalic armatures.     

Herpes simplex virus disrupts NF-kappaB regulation by blocking its recruitment on the IkappaBalpha promoter and directing the factor on viral genes

Herpes simplex viruses (HSVs) are able to hijack the host-cell IkappaB kinase (IKK)/NF-kappaB pathway, which regulates critical cell functions from apoptosis to inflammatory responses; however, the molecular mechanisms involved and the outcome of the signaling dysregulation on the host-virus interaction are mostly unknown. Here we show that in human keratinocytes HSV-1 attains a sophisticated control of the IKK/NF-kappaB pathway, inducing two distinct temporally controlled waves of IKK activity and disrupting the NF-kappaB autoregulatory mechanism. Using chromatin immunoprecipitation we demonstrate that dysregulation of the NF-kappaB-response is mediated by a virus-induced block of NF-kappaB recruitment to the promoter of the IkappaBalpha gene, encoding the main NF-kappaB-inhibitor. We also show that HSV-1 redirects NF-kappaB recruitment to the promoter of ICP0, an immediate-early viral gene with a key role in promoting virus replication. The results reveal a new level of control of cellular functions by invading viruses and suggest that persistent NF-kappaB activation in HSV-1-infected cells, rather than being a host response to the virus, may play a positive role in promoting efficient viral replication.     

Phototoxic and photoallergic skin reactions

Indirect action of sun together with different exogenous agents (systemic medications and topically applied compounds) sometimes may result in phototoxicic and photoallergic reactions. Drug-induced photosensitivity reactions refer to the development of cutaneous disease as a result of the combined effects of a drug and light (mostly spectrum within the UVA and visible light range or UVB range). The aim of the review was to show the prominent features of phototoxic and photoallergic reactions, which occur in sun-exposed areas, including face, neck, hands and forearms. Phototoxic reactions are significantly more common than photoallergic reactions and mostly resemble to exaggerated sunburn. Photoallergic reactions appear only in a minority of individuals and resemble allergic contact dermatitis on sun-exposed areas, although sometimes may extend into covered areas. Generally, the physical examination and a positive patient's history of photosensitivity reactions on substances are of great importance for the diagnostics. The treatment of these reactions includes identification and avoidance of offending agent and application of anti-inflammatory dressings, ointments and corticosteroids.     

IGF-IR Signal Transduction Protein Content and Its Activation by IGF-I in Human Placentas: Relationship with Gestational Age and Birth Weight

Introduction

The human placenta expresses the IGF-I and IGF-IR proteins and their intracellular signal components (IRS-1, AKT and mTOR). The aim of this study was to assess the IGF-IR content and activation of downstream signaling molecules in placentas from newborns who were classified by gestational age and birth weight. We studied placentas from 25 term appropriate (T-AGA), 26 term small (T-SGA), 22 preterm AGA (PT-AGA), and 20 preterm SGA (PT-SGA) newborns. The total and phosphorylated IGF-IR, IRS-1, AKT, and mTOR contents were determined by Western Blot and normalized by actin or with their respective total content. The effect of IGF-I was determined by stimulating placental explants with recombinant IGF-I 10^-8 mol/L for 15, 30, and 60 minutes.

Results

The IGF-IR content was higher in T-SGA compared to T-AGA placentas, and the IRS-1 content was higher in PT-placentas compared with their respective T-placentas. The effect of IGF-I on the phosphorylated forms of IGF-IR was increased in T-SGA (150%) and PT-SGA (300%) compared with their respective AGA placentas. In addition, AKT serine phosphorylation was higher in PT-SGA compared to PT-AGA and T-SGA placentas (90% and 390% respectively).

Conclusion

The higher protein content and response to IGF-I of IGF-IR, IRS-1, and AKT observed in SGA placentas may represent a compensatory mechanism in response to fetal growth restriction.     

An integrative approach elucidates the systematics of Sea Hayward and Cybdelis Boisduval (Lepidoptera: Nymphalidae: Biblidinae)

The systematics of the enigmatic and rather uncommon species of Sea Hayward and Cybdelis Boisduval is assessed through morphological and molecular analyses. The aim of this paper is three‐fold: (i) to ascertain the phylogenetic position of Sea and Cybdelis in Biblidinae; (ii) to determine the evolutionary relationships among species of Sea and Cybdelis; and (iii) to review the taxonomy of Sea and Cybdelis. The result of the molecular analysis recovers Sea sister to Cybdelis, and this clade sister to Eubagina (sensu Lamas, 2004 ), rendering Epicaliina (sensu Lamas, 2004 ) paraphyletic. A new tribe, Cybdelini trib.n. is erected to include Sea and Cybdelis; the other genera formerly included in Epicaliina (sensu Lamas, 2004 ), Eunica Hübner and Sevenia Koçak are assigned to Eunicini trib.rest. , and the remaining genera of Biblidinae to other previously recognized tribes, similar to those implicitly proposed by Wahlberg et al. ( 2009 ). The morphological analysis recovers similar results and the following relationships among species of Cybdelis: C. phaesyla (Hübner) (C. boliviana Salvin (C. mnasylus Doubleday (C. petronita Burmeister stat.rest. + C. thrasylla C. Felder & R. Felder stat.rest. ))). Sea and Cybdelis are recognized as distinct genera; a new subspecies, S. sophronia jenkinsi Dias, Siewert & Freitas ssp.n. , distributed from Venezuela to Bolivia along the Andes eastern foothills, is described; and C. petronita and C. thrasylla are accepted as valid species. Lectotypes for C. boliviana, C. peruviana Staudinger, C. mnasylus, C. thrasylla, C. petronita and C. mnasylus var. meridionalis Hall and a neotype for Vanessa sophronia Godart are designated. Additionally, dichotomous keys and distribution maps to all taxa are provided; male genitalia and hypandria are illustrated for all species; generic characters of the head, labial palpi and legs are illustrated; immature stages of some species also are figured. The published work has been registered on ZooBank: http://zoobank.org/urn:lsid:zoobank.org:pub:D8EBB649‐5E9D‐4218‐B1F1‐7A69DA775FD0 .