Soil biotic processes remain remarkably stable after 100-year extreme weather events in experimental grassland and heath

Climate change will increase the recurrence of extreme weather events such as drought and heavy rainfall. Evidence suggests that extreme weather events pose threats to ecosystem functioning, particularly to nutrient cycling and biomass production. These ecosystem functions depend strongly on below-ground biotic processes, including the activity and interactions among plants, soil fauna, and micro-organisms. Here, experimental grassland and heath communities of three phytodiversity levels were exposed either to a simulated single drought or to a heavy rainfall event. Both weather manipulations were repeated for two consecutive years. The magnitude of manipulations imitated the local 100-year extreme weather event. Heavy rainfall events increased below-ground plant biomass and stimulated soil enzyme activities as well as decomposition rates for both plant communities. In contrast, extreme drought did not reduce below-ground plant biomass and root length, soil enzyme activities, and cellulose decomposition rate. The low responsiveness of the measured ecosystem properties in face of the applied weather manipulations rendered the detection of significant interactions between weather events and phytodiversity impossible. Our data indicate on the one hand the close interaction between below ground plant parameters and microbial turnover processes in soil; on the other hand it shows that the plant–soil system can buffer against extreme drought events, at last for the period of investigation.     

Immunogenicity of HLA-A1-restricted peptides derived from S100A4 (metastasin 1) in melanoma patients

S100A4 (metastasin 1) belongs to the S100 family of Ca²⁺ binding proteins. While not present in most differentiated adult tissues, S100A4 is upregulated in the micromilieu of tumors. It is primarily expressed by tumor-associated macrophages, fibroblasts, and tumor endothelial cells. Due to its strong induction in tumors S100A4 is a promising target for cancer immunotherapy. By reverse immunology, using epitope prediction programs, we identified 3 HLA-A1-restricted peptide epitopes (S100A4 A1-1, A1-2, and A1-3) which are subject to human T cell responses as detected in peripheral blood of melanoma patients by means of IFN-γ ELISPOT and cytotoxicity assays. In addition, IFN-γ responses to S100A4 A1-2 can not only be induced by stimulation of T cells with peptide-loaded DC but also by stimulation with S100A4 protein-loaded DC, indicating that this epitope is indeed generated by processing of the endogenously expressed protein. In addition, S100A4 A1-2 reactive T cells demonstrate lysis of HLA-A1⁺ fibroblasts in comparison to HLA-A1⁻ fibroblasts. In summary, this HLA-A1-restricted peptide epitope is a candidate for immunotherapeutical approaches targeting S100A4-expressing cells in the tumor stroma.     

Role of proinflammatory markers and NT-proBNP in patients with an implantable cardioverter-defibrillator and an electrical storm

BackgroundSeveral studies have attempted to identify risk factors for the development of an electrical storm (ES), which is defined as ⩾3 separate ventricular tachyarrhythmic (VT/VF) events, but in the majority of studies no triggers have been found. However, little is known about the role of inflammation and NT-proBNP in patients with ES. The aim of this study was therefore to assess the relationship of Interleukin-6 (IL-6), high-sensitivity C-reactive protein (hs-CRP) and NT-proBNP serum concentrations in ICD-patients with or without single spontaneous ventricular tachyarrhythmic events (VT/VF) and in ES.MethodsMarkers were determined in 51 patients without ICD-intervention, in 15 ICD-patients with single VT/VF-episodes during 9-months follow-up and in 20 ICD-patients with ES (blood sampling performed within 60 min after fulfilling ES criteria). VT/VF-episodes were analysed by stored ICD-electrograms.ResultsAll patients had idiopathic dilated cardiomyopathy (n = 23) or coronary artery disease (n = 63). Patients with ES revealed significantly higher mean serum concentrations of all markers (IL-6 15.19 ± 10.34 pg/mL, hs-CRP 20.12 ± 14.4 mg/L, NT-proBNP 4799 ± 4596 pg/mL) compared to baseline values of patients with single VT/VF-events during follow-up (IL-6 8.37 ± 5.8 pg/mL (p = 0.03), hs-CRP 4.7 ± 5.3 mg/dL (p < 0.001), NT-proBNP 1913 ± 2665 pg/mL (p = 0.04)) and compared to baseline values of ICD-patients without device intervention (IL-6 4.62 ± 3.66 pg/mL (p < 0.001), hs-CRP 4.1 ± 3.4 mg/L (p < 0.001), NT-proBNP 1461 ± 2281 pg/mL (p < 0.001)). In 9/20 patients presenting with ES (45%) baseline values were available. All markers were significantly higher during ES compared to event-free determination (IL-6 14.54 ± 10.43 vs. 7.03 ± 2.83 pg/mL (p = 0.04), hs-CRP 19.07 ± 16.07 vs. 6.5 ± 3.9 mg/L (p = 0.02), NT-proBNP 4218 ± 2561 vs. 2099 ± 1279 pg/mL (p = 0.03)).ConclusionsElectrical storm is associated with significantly elevated IL-6, hs-CRP and NT-proBNP serum concentrations in ICD-patients with structural heart disease. Thus, ES may be triggered by proinflammatory activity. Combined intraindividual elevation of determined markers might help to identify patients at risk of impending electrical storm.     

An update on carotenoid biosynthesis in algae: phylogenetic evidence for the existence of two classes of phytoene synthase

Carotenoids play crucial roles in structure and function of the photosynthetic apparatus of bacteria, algae, and higher plants. The entry-step reaction to carotenoid biosynthesis is catalyzed by the phytoene synthase (PSY), which is structurally and functionally related in all organisms. A comparative genomic analysis regarding the PSY revealed that the green algae Ostreococcus and Micromonas possess two orthologous copies of the PSY genes, indicating an ancient gene duplication event that produced two classes of PSY in algae. However, some other green algae (Chlamydomonas reinhardtii, Chlorella vulgaris, and Volvox carteri), red algae (Cyanidioschyzon merolae), diatoms (Thalassiosira pseudonana and Phaeodactylum tricornutum), and higher plants retained only one class of the PSY gene whereas the other gene copy was lost in these species. Further, similar to the situation in higher plants recent gene duplications of PSY have occurred for example in the green alga Dunaliella salina/bardawil. As members of the PSY gene families in some higher plants are differentially regulated during development or stress, the discovery of two classes of PSY gene families in some algae suggests that carotenoid biosynthesis in these algae is differentially regulated in response to development and environmental stress as well.     

Herbicidal 4-hydroxyphenylpyruvate dioxygenase inhibitors—A review of the triketone chemistry story from a Syngenta perspective

A review, outlining the origins and subsequent development of the triketone class of herbicidal 4-hydroxyphenylpyruvate dioxygenase (HPPD) inhibitors.     

Microwave‐assisted solid‐phase peptide synthesis at 60 °C: alternative conditions with low enantiomerization

Several conditions have been used in the coupling reaction of stepwise SPPS at elevated temperature (SPPS‐ET), but we have elected the following as our first choice: 2.5‐fold molar excess of 0.04–0.08 M Boc or Fmoc‐amino acid derivative, equimolar amount of DIC/HOBt (1:1) or TBTU/DIPEA (1:3), 25% DMSO/toluene, 60 °C, conventional heating. In this study, aimed to further examine enantiomerization under such condition and study the applicability of our protocols to microwave‐SPPS, peptides containing L ‐Ser, L ‐His, L ‐Cys and/or L ‐Met were manually synthesized traditionally, at 60 °C using conventional heating and at 60 °C using microwave heating. Detailed assessment of all crude peptides (in their intact and/or fully hydrolyzed forms) revealed that, except for the microwave‐assisted coupling of L ‐Cys, all other reactions occurred with low levels of amino acid enantiomerization (<2%). Therefore, herein we (i) provide new evidences that our protocols for SPPS at 60 °C using conventional heating are suitable for routine use, (ii) demonstrate their appropriateness for microwave‐assisted SPPS by Boc and Fmoc chemistries, (iii) disclose advantages and limitations of the three synthetic approaches employed. Thus, this study complements our past research on SPPS‐ET and suggests alternative conditions for microwave‐assisted SPPS. Copyright © 2009 European Peptide Society and John Wiley & Sons, Ltd.     

Synthesis of fatty acid esters and diacylglycerols at elevated temperatures by alkalithermophilic lipases from Thermosyntropha lipolytica

LipA and LipB of Thermosyntropha lipolytica DSM 11003 as previously published are the most alkalithermophilic (pH _opt ^25°C  = 9.4–9.6, T _opt = 96°C) and thermostable (T _1/2 ^24 h  = 74–76°C) lipases currently known. The purified enzymes were analyzed in organic solvents for their ability to catalyze synthesis of diacylglycerols and various alcohol fatty acids. To obtain 100% recovery and avoid a 40% and 50% loss of catalytic activity during lyophilization of purified LipA and LipB, respectively, addition of 1 mg/ml bovine serum albumin (BSA) and 25% polyethylene glycol (PEG400) was required. LipA and LipB catalyzed esterification of fatty acids and alcohols with the highest yields for octyl oleate (LipA) and lauryl oleate (LipB) and also catalyzed synthesis of 1,3-dioleoyl glycerol, 1-oleoyl-3-lauroyl glycerol, and 1-oleoyl-3-octoyl glycerol. Isooctane was the most efficient solvent for esterification reactions at 85°C. Similar to the positional specificity for the hydrolytic reaction in aqueous solutions, LipA and LipB catalyzed in organic solvents the synthesis of diacylglycerol with esterification of position 1 and 3 with a yield of 62% for di-oleoyl glycerol. The reported conversion rates do not represent the full potential of these enzymes, since only 1/100th–1/1,000th of the protein concentrations usually used in commercial processes were available. However, use of slightly increased protein concentrations confirmed the trend to higher yields with higher protein concentrations. The obtained specificity and variety of the reactions catalyzed by LipA and LipB, and their high thermostability allowing synthesis to occur at 90°C, demonstrate their great potentials for industrial applications, particularly in structured lipid biosynthesis for substrates that are less soluble at mesobiotic temperatures.     

Anti-inflammatory effects of antibacterials on human bronchial epithelial cells

Background

Human Bronchial epithelial cells (hu-BEC) have been claimed to play a significant role in the pathogenesis of chronic inflammatory airway diseases like COPD. In this context IL-8 and GM-CSF have been shown to be key cytokines. Some antibiotics which are routinely used to treat lower respiratory tract infections have been shown to exert additional immunomodulatory or anti-inflammatory effects. We investigated whether these effects can also be detected in hu-BEC.

Methods

Hu-BEC obtained from patients undergoing lung resections were transferred to air-liquid-interface (ALI) culture. These cultures were incubated with cefuroxime (CXM, 10-62.5 mg/l), azithromycin (AZM, 0.1-1.5 mg/l), levofloxacin (LVX, 1-8 mg/l) and moxifloxacin (MXF, 1-16 mg/l). The spontaneous and TNF-α (10 ng/ml) induced expression and release of IL-8 and GM-CSF were measured using PCR and ELISA in the absence or presence of these antibiotics.

Results

The spontaneous IL-8 and GM-CSF release was significantly reduced with MXF (8 mg/l) by 37 ± 20% and 45 ± 31%, respectively (both p < 0.01). IL-8 release in TNF-α stimulated hu-BEC decreased by 16 ± 8% (p < 0.05) with AZM (1.5 mg/l). With MXF a concentration dependent decrease of IL-8 release was noted up to 39 ± 7% (p < 0.05). GM-CSF release from TNF-α stimulated hu-BEC was maximally decreased by 35 ± 24% (p < 0.01) with MXF (4 mg/l).

Conclusion

Using ALI cultures of hu-BEC we observed differential effects of antibiotics on spontaneous and TNF-α induced cytokine release. Our data suggest that MXF and AZM, beyond bactericidal effects, may attenuate the inflammatory process mediated by hu-BEC.