Regulation of apoptosis by the Ft1 protein, a new modulator of protein kinase B/Akt

The serine/threonine kinase protein kinase B (PKB)/Akt plays a central role in many cellular processes, including cell growth, glucose metabolism, and apoptosis. However, the identification and validation of novel regulators or effectors is key to future advances in understanding the multiple functions of PKB. Here we report the identification of a novel PKB binding protein, called Ft1, from a cDNA library screen using a green fluorescent protein-based protein-fragment complementation assay. We show that the Ft1 protein interacts directly with PKB, enhancing the phosphorylation of both of its regulatory sites by promoting its interaction with the upstream kinase PDK1. Further, the modulation of PKB activity by Ft1 has a strong effect on the apoptosis susceptibility of T lymphocytes treated with glucocorticoids. We demonstrate that this phenomenon occurs via a PDK1/PKB/GSK3/NF-ATc signaling cascade that controls the production of the proapoptotic hormone Fas ligand. The wide distribution of Ft1 in adult tissues suggests that it could be a general regulator of PKB activity in the control of differentiation, proliferation, and apoptosis in many cell types.     

Distribution of microcystin-producing and non-microcystin-producing Microcystis sp. in European freshwater bodies: detection of microcystins and microcystin genes in individual colonies

Microcystis is a well-known cyanobacterial genus frequently producing hepatotoxins named microcystins. Toxin production is encoded by microcystin genes (mcy). This study aims (i) to relate the mcy occurrence in individual colonies to the presence of microcystin, (ii) to assess whether morphological characteristics (morphospecies) are related to the occurrence of mcy genes, and (iii) to test whether there are geographical variations in morphospecies specificity and abundance of mcy genes. Individual colonies of nine different European countries were analysed by (1) morphological characteristics, (2) PCR to amplify a gene region within mcyA and mcyB indicative for microcystin biosynthesis, (3) matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS) to detect microcystins. Almost one hundred percent of the colonies predicted to produce microcystins by PCR analysis were found to contain microcystins. A high similarity in microcystin variants in the different colonies selected from lakes across Europe was demonstrated. The different morphospecies varied in the frequency with which they contained mcy genes. Most colonies (>75%) of M. aeruginosa and M. botrys contained the mcy genes, whereas < or = 20% of the colonies identified as M. ichthyoblabe and M. viridis gave a PCR product of the mcy genes. No colonies of M. wesenbergii gave a PCR product of either mcy gene. In addition, a positive relationship was found between the size of the colony and the frequency of those containing the mcy genes. It is concluded that the analysis of morphospecies is indicative for microcystin production, although the quantitative analysis of microcystin concentrations in water remains indispensable for hazard control.     

Somatotopic representation of action words in human motor and premotor cortex

Since the early days of research into language and the brain, word meaning was assumed to be processed in specific brain regions, which most modern neuroscientists localize to the left temporal lobe. Here we use event-related fMRI to show that action words referring to face, arm, or leg actions (e.g., to lick, pick, or kick), when presented in a passive reading task, differentially activated areas along the motor strip that either were directly adjacent to or overlapped with areas activated by actual movement of the tongue, fingers, or feet. These results demonstrate that the referential meaning of action words has a correlate in the somatotopic activation of motor and premotor cortex. This rules out a unified "meaning center" in the human brain and supports a dynamic view according to which words are processed by distributed neuronal assemblies with cortical topographies that reflect word semantics.     

What the Croatian doctors want to be learning about?

The aim of the study was to examine doctor's attitude about topics in continuing medical education (CME) using anonymous questionnaire that was given to the members of the Croatian Medical Association in Rijeka. The questions concerned doctor's interest of certain medical fields, influence of CME to their everyday practice, and importance of getting credits for re-licensure as a motive to participate in CME. The highest interest was shown for CME in emergency/intensive medicine and the lowest for transplantation medicine. The doctors in primary care showed statistically significantly higher interest for CME in family medicine, pulmology, rheumatology and rehabilitation medicine than hospital doctors. The influence of CME in everyday practice and the importance of getting credits for re-licensure as a reason to participate in CME, in the most cases, have been graded with medium grade 3. The results indicated the existence of specific needs in CME and stressed the importance of having CME with topics from clinical practice.     

Assessment of a new utero-tubal junction insemination device in dairy cattle

A new artificial insemination device for semen deposition near the utero-tubal junction in cattle (Ghent device) has been developed at the Ghent University (Belgium). In this study, the effect of the new insemination device on sperm quality was evaluated. Moreover, in a field trial 4064 dairy cows were inseminated by 12 inseminators to examine the efficacy of the device under field conditions.The Ghent device is a disposable plastic catheter which can easily follow the curvature of the uterine horns and thus reach the utero-tubal junction (UTJ). After expulsion of the inseminate with 0.7 or 1.7 ml of air, 19.0% of the insemination dose remained in the insemination catheter. Sperm loss can be diminished to 9.0% of the original insemination dose when the insemination catheter is flushed with 0.1 ml of air, followed by 0.6 ml of physiological saline solution. No toxic effect of the insemination catheter on sperm quality or fertilizing capacity was found. In the field trial, sperm were inseminated in dairy cattle which were divided in three groups. The first group was inseminated in the uterine body with the conventional insemination device, the second group in the uterine body with the Ghent device, and the third group in the tip of both uterine horns with the Ghent device. Each insemination was performed with 10 x 10(6) to 15 x 10(6) frozen-thawed spermatozoa. The pregnancy rates (PRs) were significantly affected by the insemination technique (P = 0.02), by the inseminator (P = 0.01), by heifer or cow (P < 0.01), and by the insemination number (P < 0.01). Pregnancy rates obtained with the conventional insemination device (57.6%) were significantly better than those obtained with the Ghent device in the uterine body (52.7%) (P < 0.01), but did not differ significantly from those obtained after deep insemination into both uterine horns (53.8%) (P = 0.27). It can be concluded that the Ghent device is suitable for utero-tubal junction insemination of dairy cattle under field conditions. Whether the Ghent device is also suitable for insemination with lower insemination doses is at present under investigation.     

Ac His1 [D-Phe2, K15, R16, L27] VIP (3-7)/GRF (8-27)--a VPAC1 receptor antagonist--is an inverse agonist on two constitutively active truncated VPAC1 receptors

C-terminally truncated human VPAC(1) receptors were constructed and stably transfected in Chinese hamster ovary (CHO) cells. Selected clones expressing comparable receptor densities were studied for ligand's binding properties, basal and stimulated adenylate cyclase activity. The wild-type (1-457) receptor served as reference. The binding properties of all the constructions were preserved. As judged by the intrinsic activity of the partial agonist Q(3)-VIP, the shortest receptors have a moderate impairment of the coupling efficacy to G(alpha s) protein. Cells expressing the VPAC(1) (1-436) and (1-441) truncated receptors had a two- to three-fold higher basal adenylate cyclase activity than those expressing the wild-type or the VPAC(1) (1-444), (1-433), (1-429), (1-421) and (1-398) receptor. The stimulatory effect of VIP and other agonist was preserved. This suggested that VPAC(1) (1-436) and (1-441) receptors had a constitutive activity. The selective VPAC(1) receptor antagonist Ac His(1) [D-Phe(2), K(15), R(16), L(27)] VIP (3-7)/GRF (8-27) reduced by 60% the basal activity with an EC(50) value of 3 nM comparable to its IC(50) value for binding. This agonist behaved thus like an inverse agonist on the constitutively active VPAC(1) receptors generated by C-terminal truncation and expressed in CHO cells.     

Benzimidazolone p38 inhibitors

The synthesis and in vitro p38 alpha activity of a novel series of benzimidazolone inhibitors is described. The p38 alpha SAR is consistent with a mode of binding wherein the benzimidazolone carbonyl serves as the H-bond acceptor to Met109 of p38 alpha in a manner analogous to the pyridine nitrogen of prototypical pyridylimidazole p38 inhibitors. Potent p38 alpha activity comparable to that of several previously reported p38 inhibitors is observed for this novel chemotype.     

Large-scale exploration of growth inhibition caused by overexpression of genomic fragments in Saccharomyces cerevisiae

We have screened the genome of Saccharomyces cerevisiae for fragments that confer a growth-retardation phenotype when overexpressed in a multicopy plasmid with a tetracycline-regulatable (Tet-off) promoter. We selected 714 such fragments with a mean size of 700 base-pairs out of around 84,000 clones tested. These include 493 in-frame open reading frame fragments corresponding to 454 distinct genes (of which 91 are of unknown function), and 162 out-of-frame, antisense and intergenic genomic fragments, representing the largest collection of toxic inserts published so far in yeast.     

HMGB1 is an endogenous immune adjuvant released by necrotic cells

Immune responses against pathogens require that microbial components promote the activation of antigen-presenting cells (APCs). Autoimmune diseases and graft rejections occur in the absence of pathogens; in these conditions, endogenous molecules, the so-called 'innate adjuvants', activate APCs. Necrotic cells contain and release innate adjuvants; necrotic cells also release high-mobility group B1 protein (HMGB1), an abundant and conserved constituent of vertebrate nuclei. Here, we show that necrotic HMGB1(-/-) cells have a reduced ability to activate APCs, and HMGB1 blockade reduces the activation induced by necrotic wild-type cell supernatants. In vivo, HMGB1 enhances the primary antibody responses to soluble antigens and transforms poorly immunogenic apoptotic lymphoma cells into efficient vaccines.