Wnt/β-catenin signaling plays key roles in several developmental and pathological processes. Domains of Wnt expression have been extensively investigated in the mouse, but the tissues receiving the ...signal remain largely unidentified. To define which cells respond to activated β-catenin during mammalian development, we generated the β-catenin-activated transgene driving expression of nuclear β-galactosidase reporter (BAT-gal) transgenic mice, expressing the lacZ gene under the control of β-catenin/T cell factor responsive elements. Reporter gene activity is found in known organizing centers, such as the midhindbrain border and the limb apical ectodermal ridge. Moreover, BAT-gal expression identifies novel sites of Wnt signaling, like notochord, endothelia, and areas of the adult brain, revealing an unsuspected dynamic pattern of β-catenin transcriptional activity. Expression of the transgene was analyzed in mutant backgrounds. In lipoprotein receptor-related protein 6-null homozygous mice, which lack a Wnt coreceptor, BAT-gal staining is absent in mutant tissues, indicating that BAT-gal mice are bona fide in vivo indicators of Wnt/β-catenin signaling. Analyses of BAT-gal expression in the adenomatous polyposis coli (multiple intestinal neoplasia/+) background revealed β-catenin transcriptional activity in intestinal adenomas but surprisingly not in normal crypt cells. In summary, BAT-gal mice unveil the entire complexity of Wnt/β-catenin signaling in mammals and have broad application potentials for the identification of Wnt-responsive cell populations in development and disease.
Abstract
Over the past generation, the prevalence of food allergies has risen dramatically, but the development of treatments has lagged. The commensal gut microbiome is critically involved in ...regulating allergic responses to food. Our laboratory has described a humanized model of cow’s milk allergy (CMA) in which germ-free mice are colonized with feces from healthy or CMA infants and sensitized to the cow’s milk allergen b-lactoglobulin (BLG). The healthy infant microbiota and specifically a single Clostridial species, Anaerostipes caccae, protect against the development of anaphylaxis, while the CMA microbiota does not induce this protection. We isolated a novel sub-strain of A. caccae (A. caccae_lahuc) from the feces of a healthy infant, sequenced its genome, and characterized its growth on various substrates in vitro. A. caccae_lahuc produces high concentrations of butyrate, a key immunoregulatory molecule in the gut which we hypothesize is critical to its protective impact. A. caccae_lahuc engrafts readily into the dysbiotic CMA microbiota, but co-delivery with lactulose is required for measurable butyrate production in vivo. Lactulose undergoes primary degradation by bacteria in the CMA feces which release small metabolites that A. caccae_lahuc can ferment into butyrate. Preliminary data show that this novel synbiotic biotherapy (A. caccae_lahuc + lactulose) prevents allergic responses to BLG in CMA-colonized mice as measured by serum mMCPT-1 and core body temperature upon challenge, and type 2 cytokine production in BLG-stimulated splenocytes. Further exploration into the mechanisms behind this therapeutic effect will contribute toward the larger goal of developing bacterial biotherapeutics against food allergies.
Plant hormones are considered to be important mediators of the fruit developmental signal after pollination. The role of phytohormones in tomato (Solanum lycopersicum) fruit set was investigated ...here. Transcriptome analysis of ovaries was performed using two complementary approaches: cDNA-amplified fragment length polymorphism (AFLP) and microarray analysis. The gene expression profiles obtained suggest that, in addition to auxin and gibberellin, ethylene and abscisic acid (ABA) are involved in regulating fruit set. Before fruit development, many genes involved in biotic and abiotic responses are active in the ovary. In addition, genes involved in ethylene and ABA biosynthesis were strongly expressed, suggesting relatively high ethylene and ABA concentrations before fruit set. Induction of fruit development, either by pollination or by gibberellin application, attenuated expression of all ethylene and ABA biosynthesis and response genes within 24 h. It is proposed that the function of ABA and ethylene in fruit set might be antagonistic to that of auxin and gibberellin in order to keep the ovary in a temporally protected and dormant state; either to protect the ovary tissue or to prevent fruit development before pollination and fertilization occur.
Abstract
Although the influence of urban form on microclimate and building thermal processes has been acknowledged, few studies have addressed the influence of overheating mechanisms on heterogeneous ...urban fabrics for existing historical cities. This study investigates the impact of changing urban climate on indoor temperatures by focusing on three Venice morphological patterns. Through microclimate modelling techniques, outdoor and indoor temperatures are simulated in 2020 and 2050 scenarios. Results show that the compactness of the urban fabric contributes to reducing indoor building temperatures. The analysis suggests that the increased density of shadow areas can mitigate the outdoor temperature values and reduce direct radiation on façades. When comparing the two climate scenarios 2020 and 2050, average indoor temperatures increase in the latter. However, the analysis highlights that the absence of insulation and the relatively high thermal mass of typical Venetian envelopes plays a crucial role in the building thermal processes preserving indoor comfort in a warmer climate future.
The physiological role of autophagy in the progression of liver diseases is still debated. To understand the clinical relevance of autophagy in primary e secondary hepatic tumors, we analyzed the ...expression of mTOR (mammalian target of rapamycin), a key regulator of autophagy; Raptor (regulatory-associated protein of mTOR); ULK1 (Unc-51 like kinase 1) determinant in the autophagy initiation; LC3 (microtubule-associated protein 1A/1B-light chain 3), a specific marker of autophagosomes; and p62, a selective autophagy receptor. Samples from subjects with chronic hepatitis (n.58), cirrhosis (n.12), hepatocellular carcinoma (HCC, n.56), metastases (n.48) from colorectal cancer and hyperplasia or gallbladder stones (n.7), the latter considered as controls, were examined. Gene expression analysis was carried out in n.213 tissues by absolute q-PCR, while protein expression by Western Blot in n.191 lysates, including tumoral, surrounding tumoral and normal tissues. Nonparametric statistical tests were used for comparing expression levels in the above-mentioned groups. Subgroup analysis was performed considering viral infection and chemotherapy treatment. The mTOR transcriptional level was significantly lower in metastases compared to HCC (P = 0.0001). p-mTOR(Ser2448) and LC3II/LC3I protein levels were significantly higher in metastases compared to HCC (P = 0.008 and P<0.0001, respectively). ULK(Ser757) levels were significantly higher in HCC compared to metastases (P = 0.0002) while the HCV- and HBV- related HCC showed the highest p62 levels. Chemotherapy induced a down-regulation of the p-mTOR(Ser2448) in metastases and in non-tumor surrounding tissues in treated patients compared to untreated (P = 0.001 and P = 0.005, respectively). Conclusions: the different expression of proteins considered, owning their interaction and diverse tissue microenvironment, indicate an impairment of the autophagy flux in primary liver tumors that is critical for the promotion of tumorigenesis process and a coexistence of autophagy inhibition and activation mechanisms in secondary liver tumors. Differences in mTOR and LC3 transcripts emerged in tumor-free tissues, therefore particular attention should be considered in selecting the control group.
•The Cerrado biome is highly complex in terms of LULC patterns rendering classification a big challenge.•Time series analysis and phenological metrics arise as valuable assets to perform LULC ...mapping.•Contextual information is a key factor to accurately classify vegetation and deforestation in the Cerrado.•We provide frameworks to integrate machine learning and image processing to perform LULC analysis
The Brazilian Savannah, or Cerrado, has gained vital importance in the discussions about sustainable land development after the conversion of half of its natural vegetation. For the last two decades, most of the agricultural expansion in Brazil has occurred in this biome. This is related to technological improvements in agriculture as well as to environmental compliance policies that have effectively reduced soybean expansion in the Brazilian Amazon biome. Therefore, remotely sensed imagery, pattern recognition and image processing techniques have been employed to analyze and monitor the land dynamics over Cerrado. In this work, we present a brief review on Land Use and Land Cover mapping (LULC) in the Cerrado biome from an application perspective: natural vegetation, pastureland, agriculture, and deforestation. In this review we selected some studies whose results could contribute to the development of more detailed and accurate LULC maps for the Cerrado biome.
Parts feeding is a complex logistic problem that is further complicated by the market demand for more product variety, which forces companies and manufacturers to adopt the mixed model approach in ...their assembly systems. Among the parts feeding policies for mixed-model assembly systems, there is the so-called “station-sequence” policy, where stationary kits are prepared using sequences of parts that follow the sequence of the production models. This policy can reduce stocks at the assembly stations but can also lead to potential production stops due to its low robustness. The aim of this paper is to study the station-sequence parts feeding policy, focusing on its dynamic time dependence and analyzing the effects of time and model mix perturbations on the performance of the assembly system. The study was conducted through a simulation model and a statistical analysis. The final discussion also provides a set of Industry 4.0 (I4.0) enabled solutions that are able to address the negative effect of variability on the performance of the system.
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•Grasslands exhibit distinct taxonomic and functional profiles across regions.•Grasslands show consistent taxonomic and functional profiles despite management type.•Regions have a ...core microbiome of Firmicutes, Proteobacteria, and Actinobacteriota.•Soil pH influences microbial variability in taxonomic and functional profiles.•Nitrogen cycling potentials are influenced by region, soil pH, and organic carbon.
Grasslands represent key functional ecosystems due to their global contribution to macronutrients cycling and their role as reservoirs of microbial diversity. The strategic importance of these habitats rests on their involvement in carbon and nitrogen fluxes from the atmosphere to the soil, while at the same time offering extensive sites for livestock rearing. In this study the management type, differentiated in pasture or meadow, was investigated as a variable for its possible effects on overall bacterial diversity and specific genes related to functional guilds. Its contribution was compared to that of other variables such as region, soil pH, and soil organic carbon, to rank their respective hierarchies in shaping microbial community structure. A latitudinal gradient across the European continent was studied, with three sampling groups located in Norway, France, and Northern Italy. The applied methods involved 16S DNA metabarcoding for taxonomic classification and determination of the relative abundance of the bacterial component, and quantitative PCR for the genetic determinants of bacterial and archaeal nitrification, intermediate or terminal denitrification, and nitrogen fixation. Results indicated that soil pH exerted the dominant role, affecting high taxonomy ranks and functions, along with organic carbon and region, with whom it partly covaried. In contrast, management type had no significant influence on microbial community structure and quantitative counts of functional genes. This suggests an ecological equivalence between the impacts of pasture and meadow practices, which are both perturbations that share the aspect of vegetation withdrawal by browsing or cutting, respectively.
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