Cascade of tau toxicity in inducible hippocampal brain slices and prevention by aggregation inhibitors

Mislocalization and aggregation of the axonal protein tau are hallmarks of Alzheimer's disease and other tauopathies. Here, we studied the relationship between tau aggregation, loss of spines and neurons, and reversibility by aggregation inhibitors. To this end we established an in vitro model of tauopathy based on regulatable transgenic hippocampal organotypic slice cultures prepared from mice expressing proaggregant Tau repeat domain with mutation ΔK280 (Tau(RD)ΔK). Transgene expression was monitored by a bioluminescence reporter assay. We observed abnormal tau phosphorylation and mislocalization of exogenous and endogenous tau into the somatodendritic compartment. This was paralleled by a reduction of dendritic spines, altered dendritic spine morphology, dysregulation of Ca(++) dynamics and elevated activation of microglia. Neurotoxicity was mediated by Caspase-3 activation and correlated with the expression level of proaggregant Tau(RD)ΔK. Finally, tau aggregates appeared in areas CA1 and CA3 after three weeks in vitro. Neurodegeneration was relieved by aggregation inhibitors or by switching off transgene expression. Thus the slice culture model is suitable for monitoring the development of tauopathy and the therapeutic benefit of antiaggregation drugs.

Halanaerobacter jeridensis sp. nov., isolated from a hypersaline lake

An obligatory anaerobic, moderately halophilic bacterium, designated strain CEJFG43T, was isolated from a sample of sediment collected below the salt crust on the hypersaline El Jerid lake, in southern Tunisia. The cells of this novel strain were Gram-staining-negative, non-sporulating, motile, short rods. They grew in media with 6–30 % (w/v) NaCl (optimum 15 %), at 20–60 °C (optimum 45 °C) and at pH 5.5–9.5 (optimum pH 8.3). The micro-organism fermented glucose, fructose, ribose, raffinose, galactose, mannose, sucrose, maltose, xylose, mannitol, pyruvate and glycerol. The products of glucose fermentation were lactate, ethanol, acetate, H2 and CO2. The genomic G+C DNA content of strain CEJFG43T was 33.3 mol%. Phylogenetic analysis based on 16S rRNA gene sequences indicated that strain CEJFG43T belonged in the genus Halanaerobacter and was most closely related to Halanaerobacter lacunarum DSM 6640T (95.3 % gene sequence similarity) and Halanaerobacter chitinivorans DSM 9569T (95.3 %). The predominant cellular fatty acids were non-branched (C16 : 0 and C16 : 1). Based on the phylogenetic and phenotypic evidence, strain CEJFG43T represents a novel species in the genus Halanaerobacter for which the name Halanaerobacter jeridensis sp. nov. is proposed. The type strain is CEJFG43T ( = DSM 23230T = JCM 16696T).

Kruppel-like factor 2 (KLF2) regulates monocyte differentiation and functions in mBSA and IL-1β-induced arthritis

Kruppel-like factor 2 (KLF2) plays an important role in the regulation of a variety of immune cells, including monocytes. We have previously shown that KLF2 inhibits proinflammatory activation of monocytes. However, the role of KLF2 in arthritis is yet to be investigated. In the current study, we show that recruitment of significantly greater numbers of inflammatory subset of CD11b(+)F4/80(+)Ly6C+ monocytes to the inflammatory sites in KLF2 hemizygous mice compared to the wild type littermate controls. In parallel, inflammatory mediators, MCP-1, Cox-2 and PAI-1 were significantly up-regulated in bone marrow-derived monocytes isolated from KLF2 hemizygous mice, in comparison to wild-type controls. Methylated-BSA and IL-1β-induced arthritis was more severe in KLF2 hemizygous mice as compared to the littermate wild type controls. Consistent with this observation, monocytes isolated from KLF2 hemizygous mice showed an increased number of cells matured and differentiated towards osteoclastic lineage, potentially contributing to the severity of cartilage and bone damage in induced arthritic mice. The severity of arthritis was associated with the higher expression of proteins such as HSP60, HSP90 and MMP13 and attenuated levels of pPTEN, p21, p38 and HSP25/27 molecules in bone marrow cells of arthritic KLF2 hemizygous mice compared to littermate wild type controls. The data provide new insights and evidences of KLF2-mediated transcriptional regulation of arthritis via modulation of monocyte differentiation and function.

Clinicopathologic findings in Jamaican men with prostate cancer

214

Background: Jamaican men appear to have higher age adjusted incidence rates (302/100K) than African Americans (250/100K) and Caucasians (182/100K). The purpose of this study is to examine the clinicopathologic findings in Jamaican born men presenting to Memorial Sloan-Kettering Cancer Center over a five-year period.

Methods: We reviewed the records of 150 Jamaican-born men seen at MSKCC for prostate cancer between 2003 and 2008. Age at diagnosis, highest pretreatment PSA levels, Gleason scores, and clinical stage were tabulated. Pathologic T and N stage was included for patients undergoing prostatectomy.

Results: 23 patients were excluded because the diagnosis of prostate cancer was not confirmed. The mean age at diagnosis was 59 years (37-77). The median PSA was 8 ng/mL (1-7,400 ng/mL). The distribution of Gleason scores was Gleason 6: 51 patients (40%), Gleason 7: 57 patients (45%), and Gleason 8-10: 19 patients (15%). 92% (75/81) of the men had organ confined disease by (cT1-2) by DRE. Of 46 men who had prostatectomy, 31 (67%) had organ confined disease (p T2) and 84% (37/44) were node negative.

Conclusions: Without a comparison cohort, no firm conclusions can be drawn. But, Jamaican born men presenting to MSKCC for treatment of prostate cancer do not seem to have unusually adverse pretreatment characteristics or more advanced pathological findings at prostatectomy. Our results may be affected by referral bias in favor of patients with lower risk disease. Further research is needed to determine if Jamaican men with prostate cancer present with more advanced stage or higher grade disease than men in the general population.

No significant financial relationships to disclose.

Insights into 'fermentonomics': evaluation of volatile organic compounds (VOCs) in human disease using an electronic 'e-nose'

Detection of volatile organic compounds (VOCs) is a common requirement in industry for which numerous methods are available. The electronic nose (e-nose) is an example. Rather than individual chemicals, the e-nose recognizes the 'aroma fingerprint' created by the collection of VOCs in samples, comparable to the human nose. We report on a novel application for gastrointestinal and metabolic medicine, and compare its results to mass spectrometry. Fermentation of undigested foods in the large bowel by its resident bacteria results in the creation of several chemicals including volatile gases that influence colonic and metabolic health. Using urine samples, preliminary results indicate the ability of the e-nose to distinguish between controls and those with inflammatory bowel disease or diabetes (separation rate of ∼97%). This emphasizes the different patterns of fermentation. Our term 'fermentonomics' describes the investigation and analysis of the fermentome by such non-invasive means. Such an approach has potentially wide application in medicine.

Camelimonas lactis gen. nov., sp. nov., isolated from the milk of camels

Three strains of Gram-negative, rod-shaped, non-spore-forming bacteria (M 2040T, M 1973 and M 1878-SK2), isolated from milk of camels at a camel-milk production farm in the United Arab Emirates, were investigated for their taxonomic allocation. On the basis of 16S rRNA gene sequence similarities, all three strains were shown to belong to the Alphaproteobacteria and were most closely related to Chelatococcus asaccharovorans and Chelatococcus daeguensis (95.1 and 95.2 % sequence similarity to the respective type strains). meso-Diaminopimelic acid was detected as the characteristic peptidoglycan diamino acid. The predominant compound in the polyamine pattern was spermidine, and sym-homospermidine was not detectable. The quinone system was ubiquinone Q-10. The polar lipid profile included the major compounds phosphatidylcholine and diphosphatidylglycerol and moderate amounts of phosphatidylethanolamine, phosphatidylglycerol, an unidentified glycolipid and two unidentified aminolipids. Minor lipids were also detected. The major fatty acid profile, consisting of C19 : 0 cyclo ω8c and C18 : 1 ω7c, with C18 : 0 3-OH as the major hydroxylated fatty acid, was similar to those of the genus Chelatococcus. The results of DNA–DNA hybridization experiments and physiological and biochemical tests allowed both genotypic and phenotypic differentiation of the isolates from described Chelatococcus species. Isolates M 2040T, M 1973 and M 1878-SK2 were closely related on the basis of DNA–DNA reassociation and therefore represent a single novel species. In summary, low 16S rRNA gene sequence similarities of 95 % with Chelatococcus asaccharovorans and marked differences in polar lipid profiles as well as in polyamine patterns support the description of a novel genus and species to accommodate these strains, for which the name Camelimonas lactis gen. nov., sp. nov. is proposed. The type strain of Camelimonas lactis is M 2040T (=CCUG 58638T =CCM 7696T).