Negative Evaluation Bias for Positive Self-Referential Information in Borderline Personality Disorder

Previous research has suggested that patients meeting criteria for borderline personality disorder (BPD) display altered self-related information processing. However, experimental studies on dysfunctional self-referential information processing in BPD are rare. In this study, BPD patients (N = 30) and healthy control participants (N = 30) judged positive, neutral, and negative words in terms of emotional valence. Referential processing was manipulated by a preceding self-referential pronoun, an other-referential pronoun, or no referential context. Subsequently, patients and participants completed a free recall and recognition task. BPD patients judged positive and neutral words as more negative than healthy control participants when the words had self-reference or no reference. In BPD patients, these biases were significantly correlated with self-reported attributional style, particularly for negative events, but unrelated to measures of depressive mood. However, BPD patients did not differ from healthy control participants in a subsequent free recall task and a recognition task. Our findings point to a negative evaluation bias for positive, self-referential information in BPD. This bias did not affect the storage of information in memory, but may be related to self-attributions of negative events in everyday life in BPD.     

Natural occurrence of microbial sulphur oxidation by long-range electron transport in the seafloor

Recently, a novel mode of sulphur oxidation was described in marine sediments, in which sulphide oxidation in deeper anoxic layers was electrically coupled to oxygen reduction at the sediment surface. Subsequent experimental evidence identified that long filamentous bacteria belonging to the family Desulfobulbaceae likely mediated the electron transport across the centimetre-scale distances. Such long-range electron transfer challenges some long-held views in microbial ecology and could have profound implications for sulphur cycling in marine sediments. But, so far, this process of electrogenic sulphur oxidation has been documented only in laboratory experiments and so its imprint on the seafloor remains unknown. Here we show that the geochemical signature of electrogenic sulphur oxidation occurs in a variety of coastal sediment environments, including a salt marsh, a seasonally hypoxic basin, and a subtidal coastal mud plain. In all cases, electrogenic sulphur oxidation was detected together with an abundance of Desulfobulbaceae filaments. Complementary laboratory experiments in intertidal sands demonstrated that mechanical disturbance by bioturbating fauna destroys the electrogenic sulphur oxidation signal. A survey of published geochemical data and 16S rRNA gene sequences identified that electrogenic sulphide oxidation is likely present in a variety of marine sediments with high sulphide generation and restricted bioturbation, such as mangrove swamps, aquaculture areas, seasonally hypoxic basins, cold sulphide seeps and possibly hydrothermal vent environments. This study shows for the first time that electrogenic sulphur oxidation occurs in a wide range of marine sediments and that bioturbation may exert a dominant control on its natural distribution.     

Processing of DNA structures via DNA unwinding and branch migration by the S. cerevisiae Mph1 protein

The budding yeast Mph1 protein, the putative ortholog of human FANCM, possesses a 3' to 5' DNA helicase activity and is capable of disrupting the D-loop structure to suppress chromosome arm crossovers in mitotic homologous recombination. Similar to FANCM, genetic studies have implicated Mph1 in DNA replication fork repair. Consistent with this genetic finding, we show here that Mph1 is able to mediate replication fork reversal, and to process the Holliday junction via DNA branch migration. Moreover, Mph1 unwinds 3' and 5' DNA Flap structures that bear key features of the D-loop. These biochemical results not only provide validation for a role of Mph1 in the repair of damaged replication forks, but they also offer mechanistic insights as to its ability to efficiently disrupt the D-loop intermediate.     

Applying label-free dynamic mass redistribution technology to frame signaling of G protein-coupled receptors noninvasively in living cells

Label-free dynamic mass redistribution (DMR) is a cutting-edge assay technology that enables real-time detection of integrated cellular responses in living cells. It relies on detection of refractive index alterations on biosensor-coated microplates that originate from stimulus-induced changes in the total biomass proximal to the sensor surface. Here we describe a detailed protocol to apply DMR technology to frame functional behavior of G protein-coupled receptors that are traditionally examined with end point assays on the basis of detection of individual second messengers, such as cAMP, Ca(2+) or inositol phosphates. The method can be readily adapted across diverse cellular backgrounds (adherent or suspension), including primary human cells. Real-time recordings can be performed in 384-well microtiter plates and be completed in 2 h, or they can be extended to several hours depending on the biological question to be addressed. The entire procedure, including cell harvesting and DMR detection, takes 1-2 d.     

Overcoming co‐product inhibition in the nicotinamide independent asymmetric bioreduction of activated CC‐bonds using flavin‐dependent ene‐reductases

Eleven flavoproteins from the old yellow enzyme family were found to catalyze the disproportionation (“dismutation”) of conjugated enones. Incomplete conversions, which were attributed to enzyme inhibition by the co‐product phenol could be circumvented via in situ co‐product removal by scavenging the phenol using the polymeric adsorbent MP‐carbonate. The optimized system allowed to reduce an alkene activated by ester groups in a “coupled‐substrate” approach via nicotinamide‐free hydrogen transfer with >90% conversion and complete stereoselectivity. Biotechnol. Bioeng. 2013;110: 3085–3092. © 2013 The Authors. Biotechnology and Bioengineering Published by Willey Periodicals, Inc.     

Expression of chemokine-like receptor 1 (CMKLR1) on J744A.1 macrophages co-cultured with fibroblast and/or tumor cells: modeling the influence of microenvironment

Maturation of macrophages is influenced by the composition of surrounding microenvironment. Expression of CMKLR1, the receptor for chemerin, is potentially associated with the differentiation status of macrophages. In this study, CMKLR1 was determined on peritoneal and tumor-infiltrating macrophages. CMKLR1 expression was found to be associated with the fibroblast-assisted maturation of J744A.1 monocyte/macrophage cells in the co-cultures established to model tumor microenvironment, whereas the presence of tumor cells was able to upregulate CMKLR1 expression independent of macrophage maturation. In addition, macrophages cultured with tumor cells or in tumor cell-conditioned media responded to recombinant chemerin(17-156) peptide and increased the expression of proinflammatory IL-1β, TNF-α and IL-12 p40 cytokines. The native form of chemerin (prochemerin) supplied by fibroblasts did not induce a functional response. These observations may indicate a potential role for chemerin and CMKLR1 in the regulation of inflammatory responses in the tumor microenvironment.     

Age at Death of Creutzfeldt-Jakob Disease in Subsequent Family Generation Carrying the E200K Mutation of the Prion Protein Gene

Background

The E200K mutation of the prion protein gene (PRNP) is the most frequent amino acid substitution in genetic Creutzfeldt-Jakob disease and is the only one responsible for the appearance of clustered cases in the world. In the Israel and Slovakian clusters, age of disease onset was reduced in successive generations but the absence of a clear molecular basis raised the possibility that this event was an observational bias. The aim of the present study was to investigate possible selection biases or confounding factors related to anticipation in E200K CJD patients belonging to a cluster in Southern Italy.

Methods

Clinical and demographical data of 41 parent-offspring pairs from 19 pedigrees of the Italian cluster of E200K patients were collected. Age at death of parents was compared with age at death of E200K CJD offspring. Subgroup analyses were performed for controlling possible selection biases, confounding factors, or both.

Results

The mean age at death/last follow-up of the parent generation was 71.4 years while that of CJD offspring was 59.3 years with an estimated anticipation of 12.1 years. When the same analysis was performed including only parents with CJD or carrying the E200K mutation (n = 26), the difference between offspring and parents increased to 14.8 years.

Conclusions

These results show that early age at death occurs in offspring of families carrying the E200K PRNP mutation and that this event is not linked to observational biases. Although molecular or environmental bases for this occurrence remain unsettled, this information is important for improving the accuracy of information to give to mutated carriers.     

Proteomic Analysis of the Maternal Preoptic Area in Rats

The behavior of female rats changes profoundly as they become mothers. The brain region that plays a central role in this regulation is the preoptic area, and lesions in this area eliminates maternal behaviors in rodents. The molecular background of the behavioral changes has not been established yet; therefore, in the present study, we applied proteomics to compare protein level changes associated with maternal care in the rat preoptic area. Using 2-dimensional fluorescence gel electrophoresis followed by identification of altered spots with mass spectrometry, 12 proteins were found to be significantly increased, and 6 proteins showed a significantly reduced level in mothers. These results show some similarities with a previous proteomics study of the maternal medial prefrontal cortex and genomics approaches applied to the preoptic area. Gene ontological analysis suggested that most altered proteins are involved in glucose metabolism and neuroplasticity. These proteins may support the maintenance of increased neuronal activity in the preoptic area, and morphological changes in preoptic neuronal circuits are known to take place in mothers. An increase in the level of alpha-crystallin B chain (Cryab) was confirmed by Western blotting. This small heat shock protein may also contribute to maintaining the increased activity of preoptic neurons by stabilizing protein structures. Common regulator and target analysis of the altered proteins suggested a role of prolactin in the molecular changes in the preoptic area. These results first identified the protein level changes in the maternal preoptic area. The altered proteins contribute to the maintenance of maternal behaviors and may also be relevant to postpartum depression, which can occur as a molecular level maladaptation to motherhood.

     

Human Natural Killer Cell Maturation Defect Supports In Vivo CD56bright to CD56dim Lineage Development

Two populations of human natural killer (NK) cells can be identified in peripheral blood. The majority are CD3⁻CD56^dim cells while the minority exhibits a CD3⁻CD56^bright phenotype. In vitro evidence indicates that CD56^bright cells are precursors of CD56^dim cells, but in vivo evidence is lacking. Here, we studied NK cells from a patient that suffered from a melanoma and opportunistic fungal infection during childhood. The patient exhibited a stable phenotype characterized by a reduction in the frequency of peripheral blood CD3⁻CD56^dim NK cells, accompanied by an overt increase in the frequency and absolute number of CD3⁻CD56^bright cells. These NK cells exhibited similar expression of perforin, CD57 and CD158, the major activating receptors CD16, NKp46, NKG2D, DNAM-1, and 2B4, as well as the inhibitory receptor CD94/NKG2A, on both CD56^bright and CD56^dim NK cells as healthy controls. Also, both NK cell subpopulations produced IFN-γ upon stimulation with cytokines, and CD3⁻CD56^dim NK cells degranulated in response to cytokines or K562 cells. However, upon stimulation with cytokines, a substantial fraction of CD56^dim cells failed to up-regulate CD57 and CD158, showed a reduction in the percentage of CD16⁺ cells, and CD56^bright cells did not down-regulate CD62L, suggesting that CD56^dim cells could not acquire a terminally differentiated phenotype and that CD56^bright cells exhibit a maturation defect that might result in a potential altered migration pattern. These observations, support the notion that NK cells of this patient display a maturation/activation defect that precludes the generation of mature NK cells at a normal rate accompanied by CD56^dim NK cells that cannot completely acquire a terminally differentiated phenotype. Thus, our results provide evidence that support the concept that in vivo CD56^bright NK cells differentiate into CD56^dim NK cells, and contribute to further understand human NK cell ontogeny.     

Androgen receptor drives cellular senescence

The accepted androgen receptor (AR) role is to promote proliferation and survival of prostate epithelium and thus prostate cancer progression. While growth-inhibitory, tumor-suppressive AR effects have also been documented, the underlying mechanisms are poorly understood. Here, we for the first time link AR anti-cancer action with cell senescence in vitro and in vivo. First, AR-driven senescence was p53-independent. Instead, AR induced p21, which subsequently reduced ΔN isoform of p63. Second, AR activation increased reactive oxygen species (ROS) and thereby suppressed Rb phosphorylation. Both pathways were critical for senescence as was proven by p21 and Rb knock-down and by quenching ROS with N-Acetyl cysteine and p63 silencing also mimicked AR-induced senescence. The two pathways engaged in a cross-talk, likely via PML tumor suppressor, whose localization to senescence-associated chromatin foci was increased by AR activation. All these pathways contributed to growth arrest, which resolved in senescence due to concomitant lack of p53 and high mTOR activity. This is the first demonstration of senescence response caused by a nuclear hormone receptor.