Antisense-mediated inhibition of ICAM-1 expression: a therapeutic strategy against inflammation of human periodontal tissue

Periodontal diseases, such as gingivitis and periodontitis, are caused by a mixed infection by several types of bacteria in the dental plaque, causing a chronic inflammation of the gingival mucosa. Inflammatory processes in conjunction with immune responses to bacterial attacks are generally protective. In profound periodontitis, however, hyperresponsiveness and hypersensitivity of the immune system are counterproductive because of the destruction of the affected periodontal connective tissues. The intercellular adhesion molecule type 1 (ICAM-1) plays a key role in the onset and manifestation of inflammatory responses. Thus, inhibition of ICAM-1 expression could be of therapeutic relevance for the treatment of destructive periodontitis. Here, antisense oligonucleotides (AS-ON) directed against ICAM-1 suppress protein expression and mRNA levels specifically and effectively in primary human endothelial cells of different tissue origin. Moreover, downregulation of ICAM-1 expression is also observed in AS-ON-transfected inflamed gingival mucosal tissue of patients with periodontal diseases. This work strongly suggests exploiting the local topical application of ICAM-1-directed AS-ON as a therapeutic tool against inflammatory processes of the human gingiva.     

Transgenic tobacco plants expressing Tarin 1 inhibit the growth of Pseudomonas syringae pv. tomato and the development of Spodoptera frugiperda

The protein Tarin 1, from Colocasia esculenta, was expressed in Nicotiana tabacum. Bioassays were done on plants expressing Tarin 1 at different levels using Spodoptera frugiperda larvae, various bacteria and fungi and the root‐knot nematode Meloidogyne javanica. It was found that S. frugiperda larvae fed on transformed plants had retarded and lower pupation, lower accumulated biomass and higher mortality rate than larvae fed on control plants. Also, Tarin 1 was found to inhibit the growth in vitro of Pseudomonas syringae pv. tomato. For Meloidogyne javanica, both relative replication and root damage were greater in control plants than in transformed plants, but the results were not statistically significant. This work illustrates the effects of plants expressing Tarin 1, on the growth and development of insects and bacteria, and shows its potential for pest management.     

Passive myocardial mechanical properties: meaning,measurement, models

Passive mechanical tissue properties are major determinants of myocardial contraction and relaxation and, thus, shape cardiac function. Tightly regulated, dynamically adapting throughout life, and affecting a host of cellular functions, passive tissue mechanics also contribute to cardiac dysfunction. Development of treatments and early identification of diseases requires better spatio-temporal characterisation of tissue mechanical properties and their underlying mechanisms. With this understanding, key regulators may be identified, providing pathways with potential to control and limit pathological development. Methodologies and models used to assess and mimic tissue mechanical properties are diverse, and available data are in part mutually contradictory. In this review, we define important concepts useful for characterising passive mechanical tissue properties, and compare a variety of in vitro and in vivo techniques that allow one to assess tissue mechanics. We give definitions of key terms, and summarise insight into determinants of myocardial stiffness in situ. We then provide an overview of common experimental models utilised to assess the role of environmental stiffness and composition, and its effects on cardiac cell and tissue function. Finally, promising future directions are outlined.     

Toxic Blue-green Algae Water Blooms Found in some Lakes in the German Democratic Republic

From 1977 to 1979 plankton samples were taken from 6 lakes in the German Democratic Republic (GDR) during water blooms and examined for their toxicity to homothermal animals. Microcystis aeruginosa, Aphanizomenon flos-aquae, Anabaena spiroides, and Oscillatoria redekei were dominant in the samples. With the exception of Oscillatoria redekei the algae tested had toxic effects on mice after intraperitoneal injection. The rate of survival of the test animals was particularly low when the algae were disintegrated by ultrasound or freeze-drying prior to injection, this indicating the endogenic character of the toxins. Water blooms of Microcystis aeruginosa taken from Lake Pehlitzsee (Eberswalde District) showed the highest toxicity with an LD₃₀ as high as 45 and 43.7 mg/kg, respectively. Injection of the lyophilized cells of Aphanizomenon flos-aquae brought about the same symptoms in the test animals as in the case of Microcystis, but the LD₃₀ was 200 mg/kg.     

Quantitative estimation of channeling from early glycolytic intermediates to CO in intact Escherichia coli

A pathway intermediate is said to be 'channeled' when an intermediate just made in a pathway has a higher probability of being a substrate for the next pathway enzyme compared with a molecule of the same species from the aqueous cytoplasm. Channeling is an important phenomenon because it might play a significant role in the regulation of metabolism. Whereas the usual mechanism proposed for channeling is the (often) transient interaction of sequential pathway enzymes, many of the supporting data come from results with pure enzymes and dilute cell extracts. Even when isotope dilution techniques have utilized whole-cell systems, most often only a qualitative assessment of channeling has been reported. Here we develop a method for making a quantitative calculation of the fraction channeled in glycolysis from in vivo isotope dilution experiments. We show that fructose-1,6-bisphosphate, in whole cells of Escherichia coli, was strongly channeled all the way to CO2, whereas fructose-6-phosphate was not. Because the signature of channeling is lost if any downstream intermediate prior to CO2 equilibrates with molecules in the aqueous cytosol, it was not possible to evaluate whether glucose-6-phosphate was channeled in its transformation to fructose-6-phosphate. The data also suggest that, in addition to pathway enzymes being associated with one another, some are free in the aqueous cytosol. How sensitive the degree of channeling is to growth or experimental conditions remains to be determined.     

Modulation of the epidermal growth factor receptor by the human papillomavirus type 16 E5 protein in raft cultures of human keratinocytes

It has been shown that the E5 protein of the human papillomavirus type 16 modulates epidermal growth factor receptor downregulation in monolayer cultures of human keratinocytes and mouse fibroblasts. We have now analysed the effect of this protein on the expression, the distribution and the activation of EGF receptors in raft cultures derived from an E5-transfected human keratinocyte cell line. The epithelia generated in these cultures were stratified and exhibited suprabasal expression of cytokeratins 1 and 10, which are known markers of early epidermal differentiation. In situ hybridization with an antisense riboprobe to the human papilloma virus type 16 E5 protein revealed a homogeneous gene expression within the entire epithelium of E5-transfected but not empty vector-transfected control cultures. Treatment of serum-starved rafts with EGF for 48 hours led to a strong decrease of suprabasal EGF receptors in control cultures, but not in rafts of E5-expressing cells. Under these conditions, no activated receptors were observed in control cultures, but activated receptors were still present in E5-raft cultures. Our results indicate that human papilloma virus type 16 E5-mediated modulation of EGF receptor expression occurs in a time- and structure-dependent manner in epithelial equivalents of human keratinocytes.     

Unbiased descriptor and parameter selection confirms the potential of proteochemometric modelling

Background  

Proteochemometrics is a new methodology that allows prediction of protein function directly from real interaction measurement data without the need of 3D structure information. Several reported proteochemometric models of ligand-receptor interactions have already yielded significant insights into various forms of bio-molecular interactions. The proteochemometric models are multivariate regression models that predict binding affinity for a particular combination of features of the ligand and protein. Although proteochemometric models have already offered interesting results in various studies, no detailed statistical evaluation of their average predictive power has been performed. In particular, variable subset selection performed to date has always relied on using all available examples, a situation also encountered in microarray gene expression data analysis.     

Fire and death: the pyrin domain joins the death-domain superfamily

Apoptosis and inflammation are important cellular processes that are highly regulated through specific protein-protein interactions (PPI). Proteins involved in these signaling cascades often carry PPI domains that belong to the death-domain superfamily. This includes the structurally well-characterized Death Domain (DD), the Death Effector Domain (DED) and the Caspase Recruitment Domain (CARD) subfamilies. Recently, a fourth member of the DD superfamily was identified, the Pyrin Domain (PYD). Based on sequence alignments, homology to other domains occurring in death-signalling pathways, and secondary-structure prediction, the PYD was predicted to have an overall fold similar to other DD superfamily members. Just recently, NMR structures of two PYDs have been determined. The PYD structures not only revealed the DD superfamily fold as previously predicted, but also distinct features that are characteristic exclusively for this subfamily. This review summarizes recent findings and developments regarding structural aspects of the DD superfamily, with a special emphasis on the PPIs of the DD superfamily.     

Decreased Temperature Facilitates Short-Term Sea Star Wasting Disease Survival in the Keystone Intertidal Sea Star Pisaster ochraceus

An extensive 2013 mass mortality event along the West Coast of North America due to Sea Star Wasting Disease (SSWD) has affected at least 20 species of sea stars. Among environmental factors potentially contributing to the timing of the current outbreak, increased coastal water temperatures are hypothesized to have contributed to previous and current outbreaks of SSWD. With a laboratory experiment, we tested whether cooler temperatures, similar to average winter temperatures, compared to average summer temperatures could slow the progression of morbidity or prevent SSWD mortality entirely in Pisaster ochraceus. Sea stars housed in cooler water progressed through SSWD states more slowly than sea stars housed at summer temperatures. However, the cooler temperature did not prevent SSWD mortality, and all stars died of the disease. Our data are consistent with experimental studies and field observations during previous and current outbreaks, and support the hypothesis that changes in coastal water temperatures have influenced one of the largest disease related mass mortality events in our oceans.