Evolutionary processes,dispersal limitation and climatic history shape current diversity patterns of European dragonflies

We investigated the effects of contemporary and historical factors on the spatial variation of European dragonfly diversity. Specifically, we tested to what extent patterns of endemism and phylogenetic diversity of European dragonfly assemblages are structured by 1) phylogenetic conservatism of thermal adaptations and 2) differences in the ability of post‐glacial recolonization by species adapted to running waters (lotic) and still waters (lentic). We investigated patterns of dragonfly diversity using digital distribution maps and a phylogeny of 122 European dragonfly species, which we constructed by combining taxonomic and molecular data. We calculated total taxonomic distinctiveness and mean pairwise distances across 4192 50 × 50 km equal‐area grid cells as measures of phylogenetic diversity. We compared species richness with corrected weighted endemism and standardized effect sizes of mean pairwise distances or residuals of total taxonomic distinctiveness to identify areas with higher or lower phylogenetic diversity than expected by chance. Broken‐line regression was used to detect breakpoints in diversity–latitude relationships. Dragonfly species richness peaked in central Europe, whereas endemism and phylogenetic diversity decreased from warm areas in the south‐west to cold areas in the north‐east and with an increasing proportion of lentic species. Except for species richness, all measures of diversity were consistently higher in formerly unglaciated areas south of the 0°C isotherm during the Last Glacial Maximum than in formerly glaciated areas. These results indicate that the distributions of dragonfly species in Europe were shaped by both phylogenetic conservatism of thermal adaptations and differences between lentic and lotic species in the ability of post‐glacial recolonization/dispersal in concert with the climatic history of the continent. The complex diversity patterns of European dragonflies provide an example of how integrating climatic and evolutionary history with contemporary ecological data can improve our understanding of the processes driving the geographical variation of biological diversity.     

Macrolide use in the previous years is associated with failure to eradicate Helicobacter pylori with clarithromycin‐containing regimens

Background

There is some evidence that prior use of macrolide antibiotics is a useful predictor of the likelihood of standard triple therapy failure in Helicobacter pylori eradication. In this study, we have evaluated whether previous intake of macrolides correlates with failure to eradicate H. pylori using two different first‐line clarithromycin‐containing regimens.

Materials and Methods

Retrospective study of 212 patients with H. pylori infection treated with one of two first‐line clarithromycin‐containing regimens: 108 patients treated with triple therapy for 10 days and 104 patients treated with concomitant therapy for 10 days. The intake of macrolides (clarithromycin, azithromycin, and other macrolides) prior to the eradication therapy was obtained from the electronic medical record, which contains information regarding all the medication prescribed to the patients since the year 2004.

Results

One hundred of 212 patients (47.2%) had received at least one treatment with macrolides during the years prior to the eradication therapy. H. pylori eradication rates were significantly lower in patients with previous use compared to patients without previous use of macrolides, both with triple therapy (60.8% vs 92.9%; P < .0001) and with concomitant therapy (85.7% vs 98.2%; P = .024).

Conclusions

Previous use of macrolides correlates with a low H. pylori eradication rate with triple and concomitant clarithromycin‐containing regimens. In addition, our study shows that in patients without previous use of macrolides, triple therapy achieves per‐protocol eradication rates over 90%.     

Helicobacter pylori antimicrobial resistance in a pediatric population

Background

The increasing prevalence of Helicobacter pylori (H. pylori) antimicrobial resistance, primarily for clarithromycin decreases the success of treatment. The aim of this study is to determine the local pattern of first‐line antimicrobials resistance and the eradication rate.

Material and Methods

Prospective cohort study of H. pylori infected patients (positive histological or cultural exams) treated at Centro Materno‐Infantil do Norte from January of 2013 to October of 2017. Susceptibility to 4 antibiotics: amoxicilin, metronidazole, clarithromycin, and levofloxacin were analyzed by E‐test (phenotypic resistance). The E‐test was chosen because it is simple and cost‐effective for routine susceptibility testing. Point mutations that confer clarithromycin resistance were surveyed (genotypic resistance). Eradication of H. pylori infection was defined by a negative urea breath test or fecal antigen 6‐8 weeks after the end of treatment.

Results

Of a total of 74 H. pylori infected patients, 16 were excluded because they had previous H. pylori treatment or severe systemic disease. Median age of infection cases was 15 years (3‐17 years). Eradication regimen used in all patients combined the use of 3 antibiotics (amoxicillin and metronidazole or clarithromycin) and proton pump inibhitor for 14 days and was tailored according antimicrobial susceptibility. 79.5% of the patients completed the treatment. The resistance rate for metronidazole and clarithromycin was 3.3% and 23.3%, respectively. There was no resistance for amoxicilin and levofloxacin. The rate of genotypic resistance to clarithromycin was 37.2%. The eradication rate was 97.8%.

Conclusions

The authors found a high resistance rate of H. pylori for clarithromycin in this northern portuguese pediatric center. This factor should determine a change in local current treatment, contraindicating the use of clarithromycin as a first‐line treatment for H. pylori infection in children. The high eradication rate maybe explained for the eradication treatment tailored according antimicrobial susceptibility.     

SPOCK1 promotes the invasion and metastasis of gastric cancer through Slug‐induced epithelial‐mesenchymal transition

Metastasis is a crucial impediment to the successful treatment for gastric cancer. SPOCK1 has been demonstrated to facilitate cancer metastasis in certain types of cancers; however, the role of SPOCK1 in the invasion and metastasis of gastric cancer remains elusive. SPOCK1 and epithelial‐mesenchymal transition (EMT)‐related biomarkers were detected by immunohistochemistry and Western blot in gastric cancer specimens. Other methods including stably transfected against SPOCK1 into gastric cancer cells, Western blot, migration and invasion assays in vitro and metastasis assay in vivo were also performed. The elevated expression of SPOCK1 correlates with EMT‐related markers in human gastric cancer tissue, clinical metastasis and a poor prognosis in patients with gastric cancer. In addition, knockdown of SPOCK1 expression significantly inhibits the invasion and metastasis of gastric cancer cells in vitro and in vivo, inversely, SPOCK1 overexpression results in the opposite effect. Interestingly, SPOCK1 expression has no effect on cell proliferation in vitro and in vivo. Regarding the mechanism(s) of SPOCK1‐induced cells invasion and metastasis, we prove that Slug‐induced EMT is involved in SPOCK1‐facilitating gastric cancer cells invasion and metastasis. The elevated SPOCK1 expression is closely correlated with cancer metastasis and patient survival, and SPOCK1 promotes the invasion and metastasis of gastric cancer through Slug‐mediated EMT, thereby possibly providing a novel therapeutic target for gastric cancer.     

Sphingosine‐1‐phosphate (S1P) enhances glomerular endothelial cells activation mediated by anti‐myeloperoxidase antibody‐positive IgG

Cumulating evidences suggested an important role of sphingosine‐1‐phosphate (S1P) and its receptors in regulating endothelial barrier integrity. Our previous study revealed that the circulating S1P levels and renal expression of S1PRs correlated with disease activity and renal damage in patients with antineutrophil cytoplasmic antibody (ANCA)‐associated vasculitis (AAV). This study investigated the role of S1P and its receptors in myeloperoxidase (MPO)‐ANCA‐positive IgG‐mediated glomerular endothelial cell (GEnC) activation. The effect of S1P on morphological alteration of GEnCs in the presence of MPO‐ANCA‐positive IgG was observed. Permeability assay was performed to determine endothelial monolayer activation in quantity. Both membrane‐bound and soluble ICAM‐1 and VCAM‐1 levels were measured. Furthermore, antagonists and/or agonists of various S1PRs were employed to determine the role of different S1PRs. S1P enhanced MPO‐ANCA‐positive IgG‐induced disruption of tight junction and disorganization of cytoskeleton in GEnCs. S1P induced further increase in monolayer permeability of GEnC monolayers in the presence of MPO‐ANCA‐positive IgG. S1P enhanced MPO‐ANCA‐positive IgG‐induced membrane‐bound and soluble ICAM‐1/VCAM‐1 up‐regulation of GEnCs. Soluble ICAM‐1 levels in the supernatants of GEnCs stimulated by S1P and MPO‐ANCA‐positive IgG increased upon pre‐incubation of S1PR1 antagonist, while pre‐incubation of GEnCs with the S1PR1 agonist down‐regulated sICAM‐1 level. Blocking S1PR2‐4 reduced sICAM‐1 levels in the supernatants of GEnCs stimulated by S1P and MPO‐ANCA‐positive IgG. Pre‐incubation with S1PR5 agonist could increase sICAM‐1 level in the supernatants of GEnC stimulated by S1P and MPO‐ANCA‐positive IgG. S1P can enhance MPO‐ANCA‐positive IgG‐mediated GEnC activation through S1PR2‐5.     

Caveolin‐1 down‐regulation is required for Wnt5a‐Frizzled 2 signalling in Ha‐RasV12‐induced cell transformation

Caveolin‐1 (Cav1) is down‐regulated during MK4 (MDCK cells harbouring inducible Ha‐Ras^V12 gene) transformation by Ha‐Ras^V12. Cav1 overexpression abrogates the Ha‐Ras^V12‐driven transformation of MK4 cells; however, the targeted down‐regulation of Cav1 is not sufficient to mimic this transformation. Cav1‐silenced cells, including MK4/shCav1 cells and MDCK/shCav1 cells, showed an increased cell area and discontinuous junction‐related proteins staining. Cellular and mechanical transformations were completed when MDCK/shCav1 cells were treated with medium conditioned by MK4 cells treated with IPTG (MK4+I‐CM) but not with medium conditioned by MK4 cells. Nanoparticle tracking analysis showed that Ha‐Ras^V12‐inducing MK4 cells increased exosome‐like microvesicles release compared with their normal counterparts. The cellular and mechanical transformation activities of MK4+I‐CM were abolished after heat treatment and exosome depletion and were copied by exosomes derived from MK4+I‐CM (MK4+I‐EXs). Wnt5a, a downstream product of Ha‐Ras^V12, was markedly secreted by MK4+I‐CM and MK4+I‐EXs. Suppression of Wnt5a expression and secretion using the porcupine inhibitor C59 or Wnt5a siRNA inhibited the Ha‐Ras^V12‐ and MK4+I‐CM‐induced transformation of MK4 cells and MDCK/shCav1 cells, respectively. Cav1 down‐regulation, either by Ha‐Ras^V12 or targeted shRNA, increased frizzled‐2 (Fzd2) protein levels without affecting its mRNA levels, suggesting a novel role of Cav1 in negatively regulating Fzd2 expression. Additionally, silencing Cav1 facilitated the internalization of MK4+I‐EXs in MDCK cells. These data suggest that Cav1‐dependent repression of Fzd2 and exosome uptake is potentially relevant to its antitransformation activity, which hinders the activation of Ha‐Ras^V12‐Wnt5a‐Stat3 pathway. Altogether, these results suggest that both decreasing Cav1 and increasing exosomal Wnt5a must be implemented during Ha‐Ras^V12‐driven cell transformation.     

Neuroprotective effect of formononetin in ameliorating learning and memory impairment in mouse model of Alzheimer’s disease

Alzheimer’s disease (AD) is the most common cause of dementia among elderly population. Deranged β-amyloid (Aβ) trafficking across the blood–brain barrier is known to be a critical element in the pathogenesis of AD. In the vascular endothelial cells of hippocampus, Aβ transport is mainly mediated by low-density lipoprotein-associated protein 1 (LRP1) and the receptor for advanced glycation end (RAGE) products; therefore, LRP1 and RAGE endothelial cells are potential therapeutic targets for AD. In this study, we explored the effects of Formononetin (FMN) on learning and memory improvement in APP/PS1 mice and the related mechanisms. We found that FMN significantly improved learning and memory ability by suppressing Aβ production from APP processing, RAGE-dependent inflammatory signaling and promoted LRP1-dependent cerebral Aβ clearance pathway. Moreover, FMN treatment alleviated ultrastructural changes in hippocampal vascular endothelial cells. In conclusion, we believe that FMN may be an efficacious and promising treatment for AD.