The dual benefit of arbuscular mycorrhizal fungi under soil zinc deficiency and toxicity: linking plant physiology and gene expression

Plant and Soil - Colonisation of roots by arbuscular mycorrhizal fungi (AMF) can increase plant biomass and nutrition under soil zinc (Zn) deficiency and toxicity conditions, but the genes and...     

Bifidobacteria-mediated immune system imprinting early in life

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Unsaturated fatty acids as modulators of macrophage respiratory burst in the immune response against Rhodococcus equi and Pseudomonas aeruginosa

In this paper, using the monocyte/macrophage cell line RAW264.7, we systematically investigate the impact of macrophage enrichment with unsaturated fatty acids on cellular radical synthesis. We found that the intracellular production of reactive nitrogen and oxygen intermediates depends on the activation status of the macrophages. For unstimulated macrophages PUFA enrichment resulted in an increase in cellular radical synthesis. For stimulated macrophages, instead, an impeding action of unsaturated fatty acids on the respiratory burst could be seen. Of particular importance, the impact of unsaturated fatty acids on the macrophage respiratory burst was also observed in RAW264.7 cells cocultivated with viable bacteria of the species Rhodococcus equi or Pseudomonas aeruginosa. PUFA supplementation of macrophages in the presence of R. equi or P. aeruginosa reduced the pathogen-stimulated synthesis of reactive nitrogen and oxygen intermediates. Furthermore, the unsaturated fatty acids were found to impede the expression of the myeloperoxidase gene and to reduce the activity of the enzyme. Hence, our data provide indications of a possible value of PUFA application to people suffering from chronic infections with R. equi and P. aeruginosa as a concomitant treatment to attenuate an excessive respiratory burst.     

Spatiotemporal changes of beetle communities across a tree diversity gradient

Aim Plant and arthropod diversity are often related, but data on the role of mature tree diversity on canopy insect communities are fragmentary. We compare species richness of canopy beetles across a tree diversity gradient ranging from mono‐dominant beech to mixed stands within a deciduous forest, and analyse community composition changes across space and time. Location Germany’s largest exclusively deciduous forest, the Hainich National Park (Thuringia). Methods We used flight interception traps to assess the beetle fauna of various tree species, and applied additive partitioning to examine spatiotemporal patterns of diversity. Results Species richness of beetle communities increased across the tree diversity gradient from 99 to 181 species per forest stand. Intra‐ and interspecific spatial turnover among trees contributed more than temporal turnover among months to the total γ‐beetle diversity of the sampled stands. However, due to parallel increases in the number of habitat generalists and the number of species in each feeding guild (herbivores, predators and fungivores), no proportional changes in community composition could be observed. If only beech trees were analysed across the gradient, patterns were similar but temporal (monthly) species turnover was higher compared to spatial turnover among trees and not related to tree diversity. Main conclusions The changes in species richness and community composition across the gradient can be explained by habitat heterogeneity, which increased with the mix of tree species. We conclude that understanding temporal and spatial species turnover is the key to understanding biodiversity patterns. Mono‐dominant beech stands are insufficient to conserve fully the regional species richness of the remaining semi‐natural deciduous forest habitats in Central Europe, and analysing beech alone would have resulted in the misleading conclusion that temporal (monthly) turnover contributes more to beetle diversity than spatial turnover among different tree species or tree individuals.     

RIP2 regulates growth and differentiation of normal myoblasts and of rhabdomyosarcoma cells

RIP2 is an important regulator of myoblast proliferation and differentiation. We have previously demonstrated that in the myoblast cell line C2C12 and in primary myoblasts, downregulation of rip2 gene expression is a prerequisite for differentiation. To further study the role of rip genes in myogenesis, we compared expression patterns of rip1–4 in two myoblast cell lines, C2C12 and C2F3, after the induction of differentiation. These two cell lines are derived from the same clonal origin, but differ with respect to their differentiation behaviour: specifically, the differentiation process is slower and more incomplete in C2F3 cells. When analyzing cells up to 4 days after the induction of differentiation, we found no downregulation of rip2 gene expression in C2F3 cells, which might be linked to the low differentiation potential of these cells. In addition, in contrast to C2C12 cells, the rip3 gene was not expressed in C2F3 cells. To further study the role of rip genes in the regulation of myoblast growth and differentiation, we analyzed expression patterns of rip1–4 in rhabdomyosarcoma cell lines. We found that in these cells, rip2 expression was not downregulated after the induction of differentiation. Furthermore, in contrast to normal myoblasts, they did not express the rip3 and rip4 genes. Thus, we focused on the functional role of RIP2 in rhabdomyosarcoma cells. Inhibition of rip2 gene expression in C2C12 and in rhabdomyosarcoma cells using specific siRNAs led to decreased proliferation and promoted the differentiation process of these cells. These data indicate that differential expression of rip genes can be associated with abnormal growth and differentiation behaviour of skeletal myoblasts.     

Molecular phylogeny of the Heterotrichea (Ciliophora, Postciliodesmatophora) based on small subunit rRNA gene sequences

A comprehensive molecular analysis of the phylogenetic relationships within the Heterotrichea including all described families is still lacking. For this reason, the complete nuclear small subunit (SSU) rDNA was sequenced from further representatives of the Blepharismidae and the Stentoridae. In addition, the SSU rDNA of a new, undescribed species of the genus Condylostomides (Condylostomatidae) was sequenced. The detailed phylogenetic analyses revealed a consistent branching pattern: while the terminal branches are generally well resolved, the basal relationships remain unsolved. Moreover, the data allow some conclusions about the macronuclear evolution within the genera Blepharisma, Stentor, and Spirostomum suggesting that a single, compact macronucleus represents the ancestral state.     

Case control polysomnographic studies of sleep disorders in Parkinson's disease

Background

The relationship between a number of primary sleep disorders and Parkinson''s disease (PD) is still debated. There are limited case control polysomnographic studies in PD and most of these study sample sizes are small.

Methodology/Findings

We conducted one of the largest case-control studies involving overnight polysomnographic evaluation, with prospective recruitment of unselected Parkinson''s disease patients and healthy controls from an Asian population. The cases were recruited from the specialized movement disorder outpatient clinics in a tertiary referral center, and controls from the same geographical locations. All subjects underwent an overnight polysomnographic study and a multiple sleep latency test.A total of 124 subjects including 56 patients and 68 controls frequency-matched for age and sex were included. Multivariate analysis revealed that patients had significantly shorter total sleep time than controls (p = 0.01), lower sleep efficiency (p = 0.001) and increased REM latency (p = 0.007). In patients, multivariate analysis showed that reduced total sleep time was significantly associated with increased age (p = 0.001) and increased levodopa dose (p = 0.032). The mean Insomnia Severity Index was higher in PD patients (9.0±7.1) compared to controls (3.3±3.9, p<0.001). The mean Epworth Sleepiness Scale score was higher in PD patients (9.3±5.9 vs. 5.7±4.8, p<0.001). Nocturnal arousals, obstructive sleep apnea, periodic leg movements and objective abnormal sleepiness were not increased in our patients.

Conclusions/Significance

Our case-control polysomnographic study, the first-ever performed in an Asian population, revealed altered sleep architecture and reduced sleep in PD patients compared to controls. Reduced total sleep time was associated with increased age and levodopa dose. However, nocturnal arousals, primary sleep disorders and abnormal sleepiness were not increased in our PD patients suggesting that ethnic/genetic differences may be a factor in the pathophysiology of these conditions.     

Gain of allelic gene expression for IGF-II occurs frequently in Barrett's esophagus

The IGF-II gene normally exhibits genomic imprinting, a DNA modification that allows the expression of only one of the two inherited alleles. With loss of imprinting, there is a gain of allelic gene expression (GOAGE) due to IGF-II being expressed by both alleles. GOAGE for IGF-II has been demonstrated in a number of malignancies and in normal epithelia surrounding malignancies, but not in epithelia without associated neoplasia. We hypothesized that nonneoplastic Barrett's epithelium might have GOAGE for IGF-II that could facilitate its progression to neoplasia. Endoscopic biopsies were obtained from metaplastic esophageal, normal gastric, and normal duodenal epithelia from 43 patients with Barrett's esophagus. Genomic DNA were analyzed using PCR followed by ApaI restriction enzyme digestion or allele-specific PCR to identify an ApaI polymorphism of IGF-II. cDNA from patients with the ApaI polymorphism were analyzed for IGF-II GOAGE using exon connection PCR, followed by a secondary nested PCR and ApaI restriction enzyme digestion. We found that 13 (30%) of 43 samples of Barrett's metaplasia contained the ApaI polymorphism and were thus informative for IGF-II, and sufficient material was available for GOAGE analysis in 9 of those 13 cases. GOAGE for IGF-II was demonstrated in five (56%) of those nine cases. All patients with GOAGE in Barrett's metaplasia also demonstrated GOAGE in the gastric and duodenal epithelia. In contrast, patients without GOAGE in Barrett's metaplasia also had no GOAGE in their gastric and duodenal epithelia. We conclude that in patients with Barrett's esophagus, GOAGE for IGF-II is found frequently in the metaplastic esophageal epithelium as well as in normal gastric and duodenal epithelia.     

The MMS22L-TONSL complex mediates recovery from replication stress and homologous recombination

Genome integrity is jeopardized each time DNA replication forks stall or collapse. Here we report the identification of a complex composed of MMS22L (C6ORF167) and TONSL (NFKBIL2) that participates in the recovery from replication stress. MMS22L and TONSL are homologous to yeast Mms22 and plant Tonsoku/Brushy1, respectively. MMS22L-TONSL accumulates at regions of ssDNA associated with distressed replication forks or at processed DNA breaks, and its depletion results in high levels of endogenous DNA double-strand breaks caused by an inability to complete DNA synthesis after replication fork collapse. Moreover, cells depleted of MMS22L are highly sensitive to camptothecin,?a topoisomerase I poison that impairs DNA replication progression. Finally, MMS22L and TONSL are necessary for the efficient formation of RAD51 foci after DNA damage, and their depletion impairs homologous recombination. These results indicate that MMS22L and TONSL are genome caretakers that stimulate the recombination-dependent repair of stalled or collapsed replication forks.     

Orally active and brain permeable proline amides as highly selective 5HT2c agonists for the treatment of obesity

Brain-penetrable proline amides were developed as 5HT2c agonists with more than 1000-fold binding selectivity against 5HT2b receptor. After medicinal chemistry optimization and SAR studies, orally active proline amides with robust efficacy in a rodent food intake inhibition model were uncovered.