Effects of climate change and horticultural use on the spread of naturalized alien garden plants in Europe

Climate warming is supposed to enlarge the area climatically suitable to the naturalization of alien garden plants in temperate regions. However, the effects of a changing climate on the spread of naturalized ornamentals have not been evaluated by spatially and temporarily explicit range modelling at larger scales so far. Here, we assess how climate change and the frequency of cultivation interactively determine the spread of 15 ornamental plants over the 21st century in Europe. We coupled species distribution modelling with simulations of demography and dispersal to predict range dynamics of these species in annual steps across a 250 × 250 m raster of the study area. Models were run under four scenarios of climate warming and six levels of cultivation intensity. Cultivation frequency was implemented as size of the area used for planting a species. Although the area climatically suitable to the 15 species increases, on average, the area predicted to be occupied by them in 2090 shrinks under two of the three climate change scenarios. This contradiction obviously arises from dispersal limitations that were pronounced although we assumed that cultivation is spatially adapting to the changing climate. Cultivation frequency had a much stronger effect on species spread than climate change, and this effect was non‐linear. The area occupied increased sharply from low to moderate levels of cultivation intensity, but levelled off afterwards. Our simulations suggest that climate warming will not necessarily foster the spread of alien garden plants in Europe over the next decades. However, climatically suitable areas do increase and hence an invasion debt is likely accumulating. Restricting cultivation of species can be effective in preventing species spread, irrespective of how the climate develops. However, for being successful, they depend on high levels of compliance to keep propagule pressure at a low level.     

RhoA Ambivalently Controls Prominent Myofibroblast Characteritics by Involving Distinct Signaling Routes

IntroductionRhoA has been shown to be beneficial in cardiac disease models when overexpressed in cardiomyocytes, whereas its role in cardiac fibroblasts (CF) is still poorly understood. During cardiac remodeling CF undergo a transition towards a myofibroblast phenotype thereby showing an increased proliferation and migration rate. Both processes involve the remodeling of the cytoskeleton. Since RhoA is known to be a major regulator of the cytoskeleton, we analyzed its role in CF and its effect on myofibroblast characteristics in 2 D and 3D models.ResultsDownregulation of RhoA was shown to strongly affect the actin cytoskeleton. It decreased the myofibroblast marker α-sm-actin, but increased certain fibrosis-associated factors like TGF-β and collagens. Also, the detailed analysis of CTGF expression demonstrated that the outcome of RhoA signaling strongly depends on the involved stimulus. Furthermore, we show that proliferation of myofibroblasts rely on RhoA and tubulin acetylation. In assays accessing three different types of migration, we demonstrate that RhoA/ROCK/Dia1 are important for 2D migration and the repression of RhoA and Dia1 signaling accelerates 3D migration. Finally, we show that a downregulation of RhoA in CF impacts the viscoelastic and contractile properties of engineered tissues.ConclusionRhoA positively and negatively influences myofibroblast characteristics by differential signaling cascades and depending on environmental conditions. These include gene expression, migration and proliferation. Reduction of RhoA leads to an increased viscoelasticity and a decrease in contractile force in engineered cardiac tissue.     

AT 101 induces early mitochondrial dysfunction and HMOX1 (heme oxygenase 1) to trigger mitophagic cell death in glioma cells

In most cases, macroautophagy/autophagy serves to alleviate cellular stress and acts in a pro-survival manner. However, the effects of autophagy are highly contextual, and autophagic cell death (ACD) is emerging as an alternative paradigm of (stress- and drug-induced) cell demise. AT 101 ([-]-gossypol), a natural compound from cotton seeds, induces ACD in glioma cells as confirmed here by CRISPR/Cas9 knockout of ATG5 that partially, but significantly rescued cell survival following AT 101 treatment. Global proteomic analysis of AT 101-treated U87MG and U343 glioma cells revealed a robust decrease in mitochondrial protein clusters, whereas HMOX1 (heme oxygenase 1) was strongly upregulated. AT 101 rapidly triggered mitochondrial membrane depolarization, engulfment of mitochondria within autophagosomes and a significant reduction of mitochondrial mass and proteins that did not depend on the presence of BAX and BAK1. Conversely, AT 101-induced reduction of mitochondrial mass could be reversed by inhibiting autophagy with wortmannin, bafilomycin A₁ and chloroquine. Silencing of HMOX1 and the mitophagy receptors BNIP3 (BCL2 interacting protein 3) and BNIP3L (BCL2 interacting protein 3 like) significantly attenuated AT 101-dependent mitophagy and cell death. Collectively, these data suggest that early mitochondrial dysfunction and HMOX1 overactivation synergize to trigger lethal mitophagy, which contributes to the cell killing effects of AT 101 in glioma cells.

Abbreviations: ACD, autophagic cell death; ACN, acetonitrile; AT 101, (-)-gossypol; BAF, bafilomycin A₁; BAK1, BCL2-antagonist/killer 1; BAX, BCL2-associated X protein; BH3, BCL2 homology region 3; BNIP3, BCL2 interacting protein 3; BNIP3L, BCL2 interacting protein 3 like; BP, Biological Process; CCCP, carbonyl cyanide m-chlorophenyl hydrazone; CC, Cellular Component; Con, control; CQ, chloroquine; CRISPR, clustered regularly interspaced short palindromic repeats; DMEM, Dulbecco’s Modified Eagle Medium; DTT, 1,4-dithiothreitol; EM, electron microscopy; ER, endoplasmatic reticulum; FACS, fluorescence-activated cell sorting; FBS, fetal bovine serum; FCCP, carbonyl cyanide 4-(trifluoromethoxy)phenylhydrazone; GO, Gene Ontology; HAcO, acetic acid; HMOX1, heme oxygenase 1; DKO, double knockout; LC-MS/MS, liquid chromatography coupled to tandem mass spectrometry; LPL, lipoprotein lipase, MEFs, mouse embryonic fibroblasts; mPTP, mitochondrial permeability transition pore; MTG, MitoTracker Green FM; mt-mKeima, mito-mKeima; MT-ND1, mitochondrially encoded NADH:ubiquinone oxidoreductase core subunit 1; PBS, phosphate-buffered saline; PE, phosphatidylethanolamine; PI, propidium iodide; PRKN, parkin RBR E3 ubiquitin protein ligase; SDS, sodium dodecyl sulfate; SQSTM1/p62, sequestome 1; STS, staurosporine; sgRNA, single guide RNA; SILAC, stable isotope labeling with amino acids in cell culture; TFA, trifluoroacetic acid, TMRM, tetramethylrhodamine methyl ester perchlorate; WM, wortmannin; WT, wild-type     

IKK1/2 protect human cells from TNF-mediated RIPK1-dependent apoptosis in an NF-κB-independent manner

TNF signaling is directly linked to cancer development and progression. A broad range of tumor cells is able to evade cell death induced by TNF impairing the potential anti-cancer value of TNF in therapy. Although sensitizing cells to TNF-induced death therefore has great clinical implications, detailed mechanistic insights into TNF-mediated human cell death still remain unknown. Here, we analyzed human cells by applying CRISPR/Cas9n to generate cells deficient of IKK1, IKK2, IKK1/2 and RELA. Despite stimulation with TNF resulted in impaired NF-κB activation in all genotypes compared to wildtype cells, increased cell death was observable only in IKK1/2-double-deficient cells. Cell death could be detected by Caspase-3 activation and binding of Annexin V. TNF-induced programmed cell death in IKK1/2^?/? cells was further shown to be mediated via RIPK1 in a predominantly apoptotic manner. Our findings demonstrate the IKK complex to protect from TNF-induced cell death in human cells independently to NF-κB RelA suggesting IKK1/2 to be highly promising targets for cancer therapy.     

FLORAL CORRELATES AND FITNESS CONSEQUENCES OF MATING-SYSTEM VARIATION IN TURNERA ULMIFOLIA

Outcrossing rates varied from 0% to 69% among Jamaican populations of Turnera ulmifolia. A correlation between increasing herkogamy and outcrossing rate occurred among populations. Predictions from sex-allocation theory were tested by estimating allocation to reproductive functions. Significant differences in allocation patterns occurred among populations, but they were not correlated with outcrossing rates. The fitness consequences of inbreeding were assessed in high- and low-density greenhouse experiments for nine populations with variable outcrossing rates. No evidence for inbreeding depression occurred in early portions of the life history, but multiplicative fitness functions provide evidence for inbreeding depression. We tested the prediction that selfing populations have lower levels of inbreeding depression than outcrossing populations but found no significant correlation.     

North American black-fruited hawthorns. I. Variation in floral construction,breeding system correlates,and their possible evolutionary significance inCrataegus sect.Douglasii London

Differences in the numbers of stamens and styles per flower are conspicuous features of variation in North American hawthorns (Crataegus L.). Variation in stamen number between individuals is discontinuous, with modes of approximately 20 and 10 (or fewer). In North American black-fruited sectionDouglasii Loudon the 10-stamen morphotype is exclusively polyploid, whereas the 20-stamen morphotype comprises both diploids and polyploids. Polyploidy is associated with apospory, self-fertility, and varying degrees of pollen sterility. Variation in stamen number may also be correlated with variation in distribution, phenology, leaf shape, and other features of floral morphology, leading to recognition of taxa at the specific or infraspecific level. Comparable variation in stamen number is virtually unknown in Eurasian hawthorns, as in the majority of flowering plants. In sectionDouglasii stamen number morphotypes have been recognized as either varieties or species; although correlations between stamen number and other features are not as straightforward as was previously surmised, the higher rank appears to be appropriate. These data on breeding system and morphological variation may be explainable in terms of hypotheses linking gametophytic apomixis, polyploidization, and optimal strategies for pollen dispersal.     

Genetic diversity and biogeography of native and introduced populations of Ulva pertusa (Ulvales,Chlorophyta)

Genetic diversity of native and introduced populations of Ulva pertusa (Ulvales, Chlorophyta) was examined using genetic markers of chloroplast, mitochondria and nuclear non‐coding region sequences. In the preliminary investigations to genetically identify the species for further analyses, U. pertusa was found only from temperate coasts of the more extensive collection sites including tropical coasts suggesting that it is a temperate species and basically not distributed in tropical regions. For chloroplast and mitochondrial sequences, repeating patterns of short tandem repeat sequences and nucleotide substitutions were used to recognize the haplotypes (genetic types). A total of 48 haplotypes based on combinations of chloroplast and mitochondrial haplotypes were recognized in the 244 specimens collected in the presumptive native range (Northeast Asia) and introduced populations (North America, Australia, New Zealand, Chile and Europe). Among them, 46 haplotypes (H1–H8 and H11–H48) were recognized in Northeast Asia, whereas only 1–5 haplotypes were recognized in the other areas. Nuclear microsatellite sequences were also analyzed. The lengths of the PCR products including the nuclear microsatellite region of 234 specimens were determined, and a total of 17 genotypes were recognized. Among them, 14 genotypes were found in Northeast Asia, whereas 1–7 genotypes were recognized in the other areas. Based on the results, the hypothesis that the native range of the species is in Northeast Asia was supported, and the populations outside this range were concluded to be non‐indigenous populations.     

Intracellular Staphylococcus aureus eludes selective autophagy by activating a host cell kinase

Autophagy, a catabolic pathway of lysosomal degradation, acts not only as an efficient recycle and survival mechanism during cellular stress, but also as an anti-infective machinery. The human pathogen Staphylococcus aureus (S. aureus) was originally considered solely as an extracellular bacterium, but is now recognized additionally to invade host cells, which might be crucial for persistence. However, the intracellular fate of S. aureus is incompletely understood. Here, we show for the first time induction of selective autophagy by S. aureus infection, its escape from autophagosomes and proliferation in the cytoplasm using live cell imaging. After invasion, S. aureus becomes ubiquitinated and recognized by receptor proteins such as SQSTM1/p62 leading to phagophore recruitment. Yet, S. aureus evades phagophores and prevents further degradation by a MAPK14/p38α MAP kinase-mediated blockade of autophagy. Our study demonstrates a novel bacterial strategy to block autophagy and secure survival inside the host cell.     

Swimming Behavior of Pseudomonas aeruginosa Studied by Holographic 3D Tracking

Holographic 3D tracking was applied to record and analyze the swimming behavior of Pseudomonas aeruginosa. The obtained trajectories allow to qualitatively and quantitatively analyze the free swimming behavior of the bacterium. This can be classified into five distinct swimming patterns. In addition to the previously reported smooth and oscillatory swimming motions, three additional patterns are distinguished. We show that Pseudomonas aeruginosa performs helical movements which were so far only described for larger microorganisms. Occurrence of the swimming patterns was determined and transitions between the patterns were analyzed.     

Adipose stem cell-derived extracellular matrix represents a promising biomaterial by inducing spontaneous formation of prevascular-like structures by mvECs

Tissue constructs of physiologically relevant scale require a vascular system to maintain cell viability. However, in vitro vascularization of engineered tissues is still a major challenge. Successful approaches are based on a feeder layer (FL) to support vascularization. Here, we investigated whether the supporting effect on the self-assembled formation of prevascular-like structures by microvascular endothelial cells (mvECs) originates from the FL itself or from its extracellular matrix (ECM). Therefore, we compared the influence of ECM, either derived from adipose-derived stem cells (ASCs) or adipogenically differentiated ASCs, with the classical cell-based FL. All cell-derived ECM (cdECM) substrates enabled mvEC growth with high viability. Prevascular-like structures were visualized by immunofluorescence staining of endothelial surface protein CD31 and could be observed on all cdECM and FL substrates but not on control substrate collagen I. On adipogenically differentiated ECM, longer and higher branched structures could be found compared with stem cell cdECM. An increased concentration of proangiogenic factors was found in cdECM substrates and FL approaches compared with controls. Finally, the expression of proteins associated with tube formation (E-selectin and thrombomodulin) was confirmed. These results highlight cdECM as promising biomaterial for adipose tissue engineering by inducing the spontaneous formation of prevascular-like structures by mvECs.