The genome of Syntrophorhabdus aromaticivorans strain UI provides new insights for syntrophic aromatic compound metabolism and electron flow

How aromatic compounds are degraded in various anaerobic ecosystems (e.g. groundwater, sediments, soils and wastewater) is currently poorly understood. Under methanogenic conditions (i.e. groundwater and wastewater treatment), syntrophic metabolizers are known to play an important role. This study explored the draft genome of Syntrophorhabdus aromaticivorans strain UI and identified the first syntrophic phenol‐degrading phenylphosphate synthase (PpsAB) and phenylphosphate carboxylase (PpcABCD) and syntrophic terephthalate‐degrading decarboxylase complexes. The strain UI genome also encodes benzoate degradation through hydration of the dienoyl‐coenzyme A intermediate as observed in Geobacter metallireducens and Syntrophus aciditrophicus. Strain UI possesses electron transfer flavoproteins, hydrogenases and formate dehydrogenases essential for syntrophic metabolism. However, the biochemical mechanisms for electron transport between these H₂/formate‐generating proteins and syntrophic substrate degradation remain unknown for many syntrophic metabolizers, including strain UI. Analysis of the strain UI genome revealed that heterodisulfide reductases (HdrABC), which are poorly understood electron transfer genes, may contribute to syntrophic H₂ and formate generation. The genome analysis further identified a putative ion‐translocating ferredoxin : NADH oxidoreductase (IfoAB) that may interact with HdrABC and dissimilatory sulfite reductase gamma subunit (DsrC) to perform novel electron transfer mechanisms associated with syntrophic metabolism.     

Changes in life-quality, a possible symptom of dementia development

Dementia is a chronic and irreversible brain impairment characterised by significant cognitive deficits. Severe symptoms of the aforesaid disease interfere with normal life functions and daily activities. Dementia usually develops with advancing age, i.e. after the age of 85, and when it develops in people younger than age 65, it is referred to as early onset dementia. This paper presents a 53-year-old male patient. Provisional diagnosis was established while further diagnostic workup included psycho-diagnostic assessment, neurological exam, and brain CT Such workup confirmed the development of dementia, i.e. early-onset Alzheimer's disease accompanied by depressed mood with impaired vision.     

NAADP mobilizes calcium from the endoplasmic reticular Ca(2+) store in T-lymphocytes

The target calcium store of nicotinic acid adenine dinucleotide phosphate (NAADP), the most potent endogenous calcium-mobilizing compound known to date, has been proposed to reside in the lysosomal compartment or in the endo/sarcoplasmic reticulum. This study was performed to test the hypothesis of a lysosomal versus an endoplasmic reticular calcium store sensitive to NAADP in T-lymphocytes. Pretreatment of intact Jurkat T cells with glycyl-phenylalanine 2-naphthylamide largely reduced staining of lysosomes by LysoTracker Red and abolished NAADP-induced Ca(2+) signaling. However, the inhibitory effect was not specific since Ca(2+) mobilization by d-myo-inositol 1,4,5-trisphosphate and cyclic ADP-ribose was abolished, too. Bafilomycin A1, an inhibitor of the lysosomal H(+)-ATPase, did not block or reduce NAADP-induced Ca(2+) signaling, although it effectively prevented labeling of lysosomes by LysoTracker Red. Further, previous T cell receptor/CD3 stimulation in the presence of bafilomycin A1, assumed to block refilling of lysosomal Ca(2+) stores, did not antagonize subsequent NAADP-induced Ca(2+) signaling. In contrast to bafilomycin A1, emptying of the endoplasmic reticulum by thapsigargin almost completely prevented Ca(2+) signaling induced by NAADP. In conclusion, in T-lymphocytes, no evidence for involvement of lysosomes in NAADP-mediated Ca(2+) signaling was obtained. The sensitivity of NAADP-induced Ca(2+) signaling toward thapsigargin, combined with our recent results identifying ryanodine receptors as the target calcium channel of NAADP (Dammermann, W., and Guse, A. H. (2005) J. Biol. Chem. 280, 21394-21399), rather suggest that the target calcium store of NAADP in T cells is the endoplasmic reticulum.     

Extensive MHC class I-restricted CD8 T lymphocyte responses against various yeast genera in humans

The human cellular immune response against 14 distantly related yeast species was analyzed by intracellular cytokine staining of lymphocytes after ex vivo stimulation of whole blood. While the CD4 T cell response was marginal, extensive MHC class I-restricted CD8 T cell responses were detected against a number of species including spoiling, environmental and human pathogenic yeasts. The yeast-specific CD8 T cells expressed interferon-gamma but lacked expression of CD27 and CCR7, indicating that they were end-differentiated effector memory cells. Mainly intact yeast cells rather than spheroplasts were able to induce cytokine expression in T cells demonstrating that the dominant immunogens were located in the yeast cell wall. Together these data underline the importance of the cellular immune response in protecting humans against yeast and fungal infections. And, from another perspective, recombinant yeast suggests itself as a potential vaccine candidate to efficiently induce antigen-specific CD8 T cell responses.     

Genetic Inactivation of European Sea Bass (Dicentrarchus labrax L.) Eggs Using UV-Irradiation: Observations and Perspectives

Androgenesis is a form of uniparental reproduction leading to progenies inheriting only the paternal set of chromosomes. It has been achieved with variable success in a number of freshwater species and can be attained by artificial fertilization of genetically inactivated eggs following exposure to gamma (γ), X-ray or UV irradiation (haploid androgenesis) and by restoration of diploidy by suppression of mitosis using a pressure or thermal shock. The conditions for the genetic inactivation of the maternal genome in the European sea bass (Dicentrarchus labrax L.) were explored using different combinations of UV irradiation levels and durations. UV treatments significantly affected embryo survival and generated a wide range of developmental abnormalities. Despite the wide range of UV doses tested (from 7.2 to 720 mJ.cm⁻²), only one dose (60 mJ.cm⁻².min⁻¹ with 1 min irradiation) resulted in a small percentage (14%) of haploid larvae at hatching in the initial trials as verified by flow cytometry. Microsatellite marker analyses of three further batches of larvae produced by using this UV treatment showed a majority of larvae with variable levels of paternal and maternal contributions and only one larva displaying pure paternal inheritance. The results are discussed also in the context of an assessment of the UV-absorbance characteristics of egg extracts in this species that revealed the presence of gadusol, a compound structurally related to mycosporine-like amino acids (MAAs) with known UV-screening properties.     

Complete genome sequence of Mahella australiensis type strain (50-1 BON)

Mahella australiensis Bonilla Salinas et al. 2004 is the type species of the genus Mahella, which belongs to the family Thermoanaerobacteraceae. The species is of interest because it differs from other known anaerobic spore-forming bacteria in its G+C content, and in certain phenotypic traits, such as carbon source utilization and relationship to temperature. Moreover, it has been discussed that this species might be an indigenous member of petroleum and oil reservoirs. This is the first completed genome sequence of a member of the genus Mahella and the ninth completed type strain genome sequence from the family Thermoanaerobacteraceae. The 3,135,972 bp long genome with its 2,974 protein-coding and 59 RNA genes is a part of the Genomic Encyclopedia of Bacteria and Archaea project.     

Non-contiguous finished genome sequence of the opportunistic oral pathogen Prevotella multisaccharivorax type strain (PPPA20)

Prevotella multisaccharivorax Sakamoto et al. 2005 is a species of the large genus Prevotella, which belongs to the family Prevotellaceae. The species is of medical interest because its members are able to cause diseases in the human oral cavity such as periodontitis, root caries and others. Although 77 Prevotella genomes have already been sequenced or are targeted for sequencing, this is only the second completed genome sequence of a type strain of a species within the genus Prevotella to be published. The 3,388,644 bp long genome is assembled in three non-contiguous contigs, harbors 2,876 protein-coding and 75 RNA genes and is a part of the Genomic Encyclopedia of Bacteria and Archaea project.     

Epilepsy in the elderly and depression

Epilepsy is one of the most common neurological problems affecting approximately 1% of the world's population with higher incidence among elderly individuals. Although depression is a common comorbid condition in patients with epilepsy, there is a paucity of information regarding depression in geriatric patients with epilepsy. This study analysed a group of 83 patients affected by different epilepsy phenotypes accompanied by mental disorders, especially depression. Antiepileptic and antipsychotic drug treatment has been evaluated, particularly a positive effect of the new antiepileptics (monotherapy and polytherapy) both on the reduction of seizures and mental disorders.     

Identification of key amino acid residues that determine the ability of high risk HPV16-E7 to dysregulate major histocompatibility complex class I expression

High risk human Papillomavirus (HPV) types are the major causative agents of cervical cancer. Reduced expression of major histocompatibility complex class I (MHC I) on HPV-infected cells might be responsible for insufficient T cell response and contribute to HPV-associated malignancy. The viral gene product required for subversion of MHC I synthesis is the E7 oncoprotein. Although it has been suggested that high and low risk HPVs diverge in their ability to dysregulate MHC I expression, it is not known what sequence determinants of HPV-E7 are responsible for this important functional difference. To investigate this, we analyzed the capability to affect MHC I of a set of chimeric E7 variants containing sequence elements from either high risk HPV16 or low risk HPV11. HPV16-E7, but not HPV11-E7, causes significant diminution of mRNA synthesis and surface presentation of MHC I, which depend on histone deacetylase activity. Our experiments demonstrate that the C-terminal region within the zinc finger domain of HPV-E7 is responsible for the contrasting effects of HPV11- and HPV16-E7 on MHC I. By using different loss- and gain-of-function mutants of HPV11- and HPV16-E7, we identify for the first time a residue variation at position 88 that is highly critical for HPV16-E7-mediated suppression of MHC I. Furthermore, our studies suggest that residues at position 78, 80, and 88 build a minimal functional unit within HPV16-E7 required for binding and histone deacetylase recruitment to the MHC I promoter. Taken together, our data provide new insights into how high risk HPV16-E7 dysregulates MHC I for immune evasion.