Epithelial-to-Mesenchymal Transition of RPE Cells In Vitro Confers Increased β1,6-N-Glycosylation and Increased Susceptibility to Galectin-3 Binding

Epithelial-to-mesenchymal transition (EMT) of retinal pigment epithelial cells is a crucial event in the onset of proliferative vitreoretinopathy (PVR), the most common reason for treatment failure in retinal detachment surgery. We studied alterations in the cell surface glycan expression profile upon EMT of RPE cells and focused on its relevance for the interaction with galectin-3 (Gal-3), a carbohydrate binding protein, which can inhibit attachment and spreading of human RPE cells in a dose- and carbohydrate-dependent manner, and thus bares the potential to counteract PVR-associated cellular events. Lectin blot analysis revealed that EMT of RPE cells in vitro confers a glycomic shift towards an abundance of Thomsen-Friedenreich antigen, poly-N-acetyllactosamine chains, and complex-type branched N-glycans. Using inhibitors of glycosylation we found that both, binding of Gal-3 to the RPE cell surface and Gal-3-mediated inhibition of RPE attachment and spreading, strongly depend on the interaction of Gal-3 with tri- or tetra-antennary complex type N-glycans and sialylation of glycans but not on complex-type O-glycans. Importantly, we found that β1,6 N-acetylglucosaminyltransferase V (Mgat5), the key enzyme catalyzing the synthesis of tetra- or tri-antennary complex type N-glycans, is increased upon EMT of RPE cells. Silencing of Mgat5 by siRNA and CRISPR-Cas9 genome editing resulted in reduced Gal-3 binding. We conclude from these data that binding of recombinant Gal-3 to the RPE cell surface and inhibitory effects on RPE attachment and spreading largely dependent on interaction with Mgat5 modified N-glycans, which are more abundant on dedifferentiated than on the healthy, native RPE cells. Based on these findings we hypothesize that EMT of RPE cells in vitro confers glycomic changes, which account for high affinity binding of recombinant Gal-3, particularly to the cell surface of myofibroblastic RPE. From a future perspective recombinant Gal-3 may disclose a therapeutic option allowing for selectively targeting RPE cells with pathogenic relevance for development of PVR.     

The Effect of Age,Parity and Body Mass Index on the Efficacy,Safety, Placement and User Satisfaction Associated With Two Low-Dose Levonorgestrel Intrauterine Contraceptive Systems: Subgroup Analyses of Data From a Phase III Trial

Objective

Two low-dose levonorgestrel intrauterine contraceptive systems (LNG-IUSs; total content 13.5 mg [average approx. 8 μg/24 hours over the first year; LNG-IUS 8] and total content 19.5 mg [average approx. 13 μg/24 hours over the first year; LNG-IUS 13]) have previously been shown to be highly effective (3-year Pearl Indices: 0.33 and 0.31, respectively), safe and well tolerated. The present subgroup analyses evaluated whether or not outcomes were affected by parity, age (18–25 vs 26–35 years), or body mass index (BMI, <30 vs ≥30 kg/m²).

Methods

Nulliparous and parous women aged 18‒35 years with regular menstrual cycles (21‒35 days) requesting contraception were randomized to 3 years of LNG-IUS 8 or LNG-IUS 13 use.

Results

In the LNG-IUS 8 and LNG-IUS 13 groups, 1432 and 1452 women, respectively, had a placement attempted and were included in the full analysis set; 39.2%, 39.2% and 17.1% were 18–25 years old, nulliparous and had a BMI ≥30 kg/m², respectively. Both systems were similarly effective regardless of age, parity or BMI; the subgroup Pearl Indices had widely overlapping 95% confidence intervals. Placement of LNG-IUS 8 and LNG-IUS 13 was easier (p < 0.0001) and less painful (p < 0.0001) in women who had delivered vaginally than in women who had not. The complete/partial expulsion rate was 2.2–4.2% across all age and parity subgroups and higher in parous than in nulliparous women (p = 0.004). The incidence of pelvic inflammatory disease was 0.1–0.6% across all age and parity subgroups: nulliparous and younger women were not at higher risk than parous and older women, respectively. The ectopic pregnancy rate was 0.3–0.4% across all age and parity subgroups. Across all age and parity subgroups, the 3-year completion rate was 50.9–61.3% for LNG-IUS 8 and 57.9–61.1% for LNG-IUS 13, and was higher (p = 0.0001) among older than younger women in the LNG-IUS 8 group only.

Conclusions

LNG-IUS 8 and LNG-IUS 13 were highly effective, safe and well tolerated regardless of age or parity.

Trial Registration

Clinical trials.gov NCT00528112     

Task Type Affects Location of Language-Positive Cortical Regions by Repetitive Navigated Transcranial Magnetic Stimulation Mapping

Objectives

Recent repetitive TMS (rTMS) mapping protocols for language mapping revealed deficits of this method, mainly in posterior brain regions. Therefore this study analyzed the impact of different language tasks on the localization of language-positive brain regions and compared their effectiveness, especially with regard to posterior brain regions.

Methods

Nineteen healthy, right-handed subjects performed object naming, pseudoword reading, verb generation, and action naming during rTMS language mapping of the left hemisphere. Synchronically, 5 Hz/10 pulses were applied with a 0 ms delay

Results

The object naming task evoked the highest error rate (14%), followed by verb generation (13%) and action naming (11%). The latter revealed more errors in posterior than in anterior areas. Pseudoword reading barely generated errors, except for phonological paraphasias.

Conclusions

In general, among the evaluated language tasks, object naming is the most discriminative task to detect language-positive regions via rTMS. However, other tasks might be used for more specific questions.     

Fetal microchimerism in kidney biopsies of lupus nephritis patients may be associated with a beneficial effect

IntroductionMicrochimeric male fetal cells (MFCs) have been associated with systemic lupus erythematosus, and published studies have further correlated MFC with lupus nephritis (LN). In the present study, we evaluated the frequency of MFC in the renal tissue of patients with LN.MethodsTwenty-seven renal biopsies were evaluated: Fourteen were from women with clinical and laboratory findings of LN, and thirteen were from controls. Genomic DNA was extracted from kidney biopsies, and the male fetal DNA was quantified using real-time quantitative polymerase chain reactions for the detection of specific Y chromosome sequences.ResultsMFCs were detected in 9 (64%) of 14 of patients with LN, whereas no MFCs were found in the control group (P = 0.0006). No differences in pregnancy history were found between patients with LN and the control group. Significantly higher amounts of MFCs were found in patients with LN with serum creatinine ≤1.5 mg/dl. Furthermore, women with MFCs had significantly better renal function at the time of biopsy (P = 0.03). In contrast, patients with LN without MFCs presented with more severe forms of glomerulonephritis (World Health Organization class IV = 60% and class V = 40%).ConclusionsOur data indicate a high prevalence of MFCs in renal biopsy specimens from women with LN, suggesting a role for MFCs in the etiology of LN. The present report also provides some evidence that MFCs could have a beneficial effect in this disease.

Electronic supplementary material

The online version of this article (doi:10.1186/s13075-015-0615-4) contains supplementary material, which is available to authorized users.     

Water Distribution in Bacterial Spores: A Key Factor in Heat Resistance

The role of water, its distribution and its implication in the heat resistance of dried spores was investigated using DSC (Differential Scanning Calorimetry). Bacillus subtilis spores equilibrated at different water activity levels were heat treated under strictly controlled conditions. The temperature was increased linearly in pans with different resistances to pressure. Data from the heat-related transitions occurring in the spores were recorded and spore viability was assessed at different stages during DSC. The thermodynamic transitions observed were related to the water status in the spores and spore survival. The results demonstrated that water still remained in the spore core when water activity was as low as 0.13. The first transition occurred at around 150 °C and was assumed to be related to a mobile fraction of water from the outer layers of the spore. The second occurred at around 200 °C, which could correspond to a fraction of water embedded in the spore core. Moreover, the results showed that spore destruction during heating was favored by the amount of water remaining in the spore. The changes in their structure were also evaluated by FTIR (Fourier Transform Infrared Spectroscopy). This work offers new understanding about the distribution of water in spores and presents new elements on the heat resistance of spores in relation to their water content.     

HPTN 071 (PopART): A Cluster-Randomized Trial of the Population Impact of an HIV Combination Prevention Intervention Including Universal Testing and Treatment: Mathematical Model

Background

The HPTN 052 trial confirmed that antiretroviral therapy (ART) can nearly eliminate HIV transmission from successfully treated HIV-infected individuals within couples. Here, we present the mathematical modeling used to inform the design and monitoring of a new trial aiming to test whether widespread provision of ART is feasible and can substantially reduce population-level HIV incidence.

Methods and Findings

The HPTN 071 (PopART) trial is a three-arm cluster-randomized trial of 21 large population clusters in Zambia and South Africa, starting in 2013. A combination prevention package including home-based voluntary testing and counseling, and ART for HIV positive individuals, will be delivered in arms A and B, with ART offered universally in arm A and according to national guidelines in arm B. Arm C will be the control arm. The primary endpoint is the cumulative three-year HIV incidence.We developed a mathematical model of heterosexual HIV transmission, informed by recent data on HIV-1 natural history. We focused on realistically modeling the intervention package. Parameters were calibrated to data previously collected in these communities and national surveillance data.We predict that, if targets are reached, HIV incidence over three years will drop by >60% in arm A and >25% in arm B, relative to arm C. The considerable uncertainty in the predicted reduction in incidence justifies the need for a trial. The main drivers of this uncertainty are possible community-level behavioral changes associated with the intervention, uptake of testing and treatment, as well as ART retention and adherence.

Conclusions

The HPTN 071 (PopART) trial intervention could reduce HIV population-level incidence by >60% over three years. This intervention could serve as a paradigm for national or supra-national implementation. Our analysis highlights the role mathematical modeling can play in trial development and monitoring, and more widely in evaluating the impact of treatment as prevention.     

Contrasting responses of seedling and sapling densities to livestock density in the Mongolian forest-steppe

The past and present regeneration of Siberian larch (Larix sibirica) was studied in the forest-steppe of the Mongolian Altai, an area which has experienced an increase in annual mean temperature by 2.1 °C since 1940 and is subjected to grazing by mixed herds of livestock owned by pastoral nomads. Past regeneration was reconstructed from tree rings and present regeneration was analyzed by surveying seedlings, sapling-sized trees and the occurrence of viable larch seeds in the soil seed bank. Forest regeneration occurred throughout the twentieth and the early twenty-first centuries in the forest interiors, but ceased after the late 1970s at forest edges. The density of sapling-sized larch trees decreased with livestock density linearly in the interior and exponentially at the edge. Most sapling-sized trees had visible damage from livestock browsing, which also manifested in wood-anatomical anomalies. By contrast, the densities of 1- and 2-year old seedlings increased with livestock density at the forest edge, suggesting that seedlings in this habitat benefitted from the reduction in competition intensity due to livestock grazing. This relationship also suggests that larch seedlings, in contrast to sapling-sized trees, were avoided by the livestock, as otherwise removal by the herbivores should have counteracted the promotion due to reduced competition. Near-consistency of the correlations of total livestock and goat densities with sapling and seedling densities suggests that the control of larch regeneration is primarily a function of goat density, which have tripled in the Mongolian livestock during the past 20 years for economic reasons.     

Significance of Over-Mature and Decaying Trees for Carbon Stocks in a Central European Natural Spruce Forest

Old-growth forests are important stores for carbon as they may accumulate C for centuries. The alteration of biomass and soil carbon pools across the development stages of a forest dynamics cycle has rarely been quantified. We studied the above- and belowground C stocks in the five forest development stages (regeneration to decay stage) of a montane spruce (Picea abies) forest of the northern German Harz Mountains, one of Central Europe’s few forests where the natural forest dynamics have not been disturbed by man for several centuries. The over-mature and decay stages had the largest total (up to 480 Mg C ha^?1) and aboveground biomass carbon pools (200 Mg C ha^?1) with biomass C stored in dead wood in the decay stage. The soil C pool (220–275 Mg C ha^?1, 0–60 cm) was two to three times larger than in temperate lowland spruce forests and remained invariant across the forest dynamics cycle. On the landscape level, taking into account the frequency of the five forest development stages, the total carbon pool was approximately 420 Mg C ha^?1. The results evidence the high significance of over-mature and decaying stages of temperate mountain forests not only for conserving specialized forest organisms but also for their large carbon storage potential.     

Responses of Temperate Forests to Nitrogen Deposition: Testing the Explanatory Power of Modeled Deposition Datasets for Vegetation Gradients

Ecosystems - Eutrophication due to increased nitrogen concentrations is known to alter species composition and threaten sensitive habitat types. The contribution of atmospheric nitrogen deposition...