Nutrient enrichment increased species richness of leaf litter fungal assemblages in a tropical forest

Microbial communities play a major role in terrestrial ecosystem functioning, but the determinates of their diversity and functional interactions are not well known. In this study, we explored leaf litter fungal diversity in a diverse Panama lowland tropical forest in which a replicated factorial N, P, K and micronutrient fertilization experiment of 40 × 40 m plots had been ongoing for nine years. We extracted DNA from leaf litter samples and used fungal‐specific amplification and a 454 pyrosequencing approach to sequence two loci, the nuclear ribosomal internal transcribed spacer (ITS) region and the nuclear ribosomal large subunit (LSU) D1 region. Using a 95% sequence similarity threshold for ITS1 spacer recovered a total of 2523 OTUs, and the number of unique ITS1 OTUs per 0.5–1.0 g leaf litter sample ranged from 55 to 177. Ascomycota were the dominant phylum among the leaf litter fungi (71% of the OTUs), followed by Basidiomycota (26% of the OTUs). In contrast to our expectations based on temperate ecosystems, long‐term addition of nutrients increased, rather than decreased, species richness relative to controls. Effect of individual nutrients was more subtle and seen primarily as changes in community compositions especially at lower taxonomic levels, rather than as significant changes in species richness. For example, plots receiving P tended to show a greater similarity in community composition compared to the other nutrient treatments, the +PK, +NK and +NPK plots appeared to be more dominated by the Nectriaceae than other treatments, and indicator species for particular nutrient combinations were identified.     

Trisubstituted and tetrasubstituted pyrazolines as a novel class of cell-growth inhibitors in tumor cells with wild type p53

Derivatives with scaffolds of 1,3,5-tri-substituted pyrazoline and 1,3,4,5-tetra-substituted pyrazoline were synthesized and tested for their inhibitory effects versus the p53^+/+ HCT116 and p53^?/? H1299 human tumor cell lines. Several compounds were active against the two cell lines displaying IC₅₀ values in the low micromolar range with a clearly more pronounced effect on the p53^+/+ HCT116 cells. The compound class shows excellent developability due to the modular synthesis, allowing independent optimization of all three to four key substituents to improve the properties of the molecules.     

Association of a common TLR-6 polymorphism with coronary artery disease – implications for healthy ageing?

Background

The pro-inflammatory status of the elderly triggers most of the age-related diseases such as cancer and atherosclerosis. Atherosclerosis, the leading cause world wide of morbidity and death, is an inflammatory disease influenced by life-style and genetic host factors. Stimuli such as oxLDL or microbial ligands have been proposed to trigger inflammation leading to atherosclerosis. It has recently been shown that oxLDL activates immune cells via the Toll-like receptor (TLR) 4/6 complex. Several common single nucleotide polymorphisms (SNPs) of the TLR system have been associated with atherosclerosis. To investigate the role of TLR-6 we analyzed the association of the TLR-6 SNP Pro249Ser with atherogenesis.

Results

Genotyping of two independent groups with CAD, as well as of healthy controls revealed a significant association of the homozygous genotype with a reduced risk for atherosclerosis (odds ratio: 0.69, 95% CI 0.51-0.95, P?=?0.02). In addition, we found a trend towards an association with the risk of restenosis after transluminal coronary angioplasty (odds ratio: 0.53, 95% CI 0.24-1.16, P?=?0.12). In addition, first evidence is presented that the frequency of this protective genotype increases in a healthy population with age. Taken together, our results define a role for TLR-6 and its genetic variations in modulating the inflammatory response leading to atherosclerosis.

Conclusions

These results may lead to a better risk stratification, and potentially to an improved prophylactic treatment of high-risk populations. Furthermore, the protective effect of this polymorphism may lead to an increase of this genotype in the healthy elderly and may therefore be a novel genetic marker for the well-being during aging.

     

Spectrophotometric measurements of human tissues for the detection of subjacent blood vessels in an endonasal endoscopic surgical approach

Thin slices of human tissues are characterized concerning reflection and transmission in a wavelength range from 400 to 1700 nm. The results are primarily useful to find a wavelength for the detection of subjacent blood vessels during surgical procedures, especially neurological surgery. The measurements have been conducted using a customized measuring station, utilizing two halogen bulb lamps and two spectrometers. This paper focuses on creating a data base with the optical properties of artery, brain, bone, nasal mucosa, and nerve. The spectral distributions are compared among each other, similarities and differences are pointed out. Each tissue has got unique spectral characteristics, whereas typical absorption bands can be found in the overall tissues, especially hemoglobin and water absorption bands. The reflectivity maxima are typically located in the red or near‐infrared. All the transmission maxima are located between 1075 nm and 1100 nm. The measurements have been conducted at the Institute of Anatomy at the University of Leipzig. (© 2013 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

RIG-I Detects Triphosphorylated RNA of Listeria monocytogenes during Infection in Non-Immune Cells

The innate immune system senses pathogens by pattern recognition receptors in different cell compartments. In the endosome, bacteria are generally recognized by TLRs; facultative intracellular bacteria such as Listeria, however, can escape the endosome. Once in the cytosol, they become accessible to cytosolic pattern recognition receptors, which recognize components of the bacterial cell wall, metabolites or bacterial nucleic acids and initiate an immune response in the host cell. Current knowledge has been focused on the type I IFN response to Listeria DNA or Listeria-derived second messenger c-di-AMP via the signaling adaptor STING. Our study focused on the recognition of Listeria RNA in the cytosol. With the aid of a novel labeling technique, we have been able to visualize immediate cytosolic delivery of Listeria RNA upon infection. Infection with Listeria as well as transfection of bacterial RNA induced a type-I-IFN response in human monocytes, epithelial cells or hepatocytes. However, in contrast to monocytes, the type-I-IFN response of epithelial cells and hepatocytes was not triggered by bacterial DNA, indicating a STING-independent Listeria recognition pathway. RIG-I and MAVS knock-down resulted in abolishment of the IFN response in epithelial cells, but the IFN response in monocytic cells remained unaffected. By contrast, knockdown of STING in monocytic cells reduced cytosolic Listeria-mediated type-I-IFN induction. Our results show that detection of Listeria RNA by RIG-I represents a non-redundant cytosolic immunorecognition pathway in non-immune cells lacking a functional STING dependent signaling pathway.     

Effects of Bacillus amyloliquefaciens FZB42 on Lettuce Growth and Health under Pathogen Pressure and Its Impact on the Rhizosphere Bacterial Community

The soil-borne pathogen Rhizoctonia solani is responsible for crop losses on a wide range of important crops worldwide. The lack of effective control strategies and the increasing demand for organically grown food has stimulated research on biological control. The aim of the present study was to evaluate the rhizosphere competence of the commercially available inoculant Bacillus amyloliquefaciens FZB42 on lettuce growth and health together with its impact on the indigenous rhizosphere bacterial community in field and pot experiments. Results of both experiments demonstrated that FZB42 is able to effectively colonize the rhizosphere (7.45 to 6.61 Log ₁₀ CFU g⁻¹ root dry mass) within the growth period of lettuce in the field. The disease severity (DS) of bottom rot on lettuce was significantly reduced from severe symptoms with DS category 5 to slight symptom expression with DS category 3 on average through treatment of young plants with FZB42 before and after planting. The 16S rRNA gene based fingerprinting method terminal restriction fragment length polymorphism (T-RFLP) showed that the treatment with FZB42 did not have a major impact on the indigenous rhizosphere bacterial community. However, the bacterial community showed a clear temporal shift. The results also indicated that the pathogen R. solani AG1-IB affects the rhizosphere microbial community after inoculation. Thus, we revealed that the inoculant FZB42 could establish itself successfully in the rhizosphere without showing any durable effect on the rhizosphere bacterial community.     

Rosiglitazone Treatment of Type 2 Diabetic db/db Mice Attenuates Urinary Albumin and Angiotensin Converting Enzyme 2 Excretion

Alterations within the renal renin angiotensin system play a pivotal role in the development and progression of cardiovascular and renal disease. Angiotensin converting enzyme 2 (ACE2) is highly expressed in renal tubules and has been shown to be renoprotective in diabetes. The protease, a disintegrin and metalloprotease (ADAM) 17, is involved in the ectodomain shedding of several transmembrane proteins including ACE2. Renal ACE2 and ADAM17 were significantly increased in db/db mice compared to controls. We investigated the effect of the insulin sensitizer, rosiglitazone, on albuminuria, renal ADAM17 protein expression and ACE2 shedding in db/db diabetic mice. Rosiglitazone treatment of db/db mice normalized hyperglycemia, attenuated renal injury and decreased urinary ACE2 and renal ADAM17 protein expression. Urinary excreted ACE2 is enzymatically active. Western blot analysis of urinary ACE2 demonstrated two prominent immunoreactive bands at approximately 70 & 90 kDa. The predominant immunoreactive band is approximately 20 kDa shorter than the one demonstrated for kidney lysate, indicating possible ectodomain shedding of active renal ACE2 in the urine. Therefore, it is tempting to speculate that renoprotection of rosiglitazone could be partially mediated via downregulation of renal ADAM17 and ACE2 shedding. In addition, there was a positive correlation between blood glucose, urinary albumin, plasma glucagon, and triglyceride levels with urinary ACE2 excretion. In conclusion, urinary ACE2 could be used as a sensitive biomarker of diabetic nephropathy and for monitoring the effectiveness of renoprotective medication.     

Discovery and characterization of COVA322, a clinical-stage bispecific TNF/IL-17A inhibitor for the treatment of inflammatory diseases

Biologic treatment options such as tumor necrosis factor (TNF) inhibitors have revolutionized the treatment of inflammatory diseases, including rheumatoid arthritis. Recent data suggest, however, that full and long-lasting responses to TNF inhibitors are limited because of the activation of the pro-inflammatory T_H17/interleukin (IL)-17 pathway in patients. Therefore, dual TNF/IL-17A inhibition is an attractive avenue to achieve superior efficacy levels in such diseases. Based on the marketed anti-TNF antibody adalimumab, we generated the bispecific TNF/IL-17A-binding FynomAb COVA322. FynomAbs are fusion proteins of an antibody and a Fyn SH3-derived binding protein. COVA322 was characterized in detail and showed a remarkable ability to inhibit TNF and IL-17A in vitro and in vivo. Through its unique mode-of-action of inhibiting simultaneously TNF and the IL-17A homodimer, COVA322 represents a promising drug candidate for the treatment of inflammatory diseases. COVA322 is currently being tested in a Phase 1b/2a study in psoriasis (ClinicalTrials.gov Identifier: NCT02243787).