Intersections between innate immune response and gastric cancer development.

Worldwide, gastric cancer (GC) is the fifth most commonly diagnosed malignancy. It has a reduced prevalence but has maintained its poor prognosis being the fourth leading cause of deaths related to cancer. The highest mortality rates occur in Asian and Latin American countries, where cases are usually diagnosed at advanced stages. Overall, GC is viewed as the consequence of a multifactorial process, involving the virulence of the Helicobacter pylori (H. pylori) strains, as well as some environmental factors, dietary habits, and host intrinsic factors. The tumor microenvironment in GC appears to be chronically inflamed which promotes tumor progression and reduces the therapeutic opportunities. It has been suggested that inflammation assessment needs to be measured qualitatively and quantitatively, considering cell-infiltration types, availability of receptors to detect damage and pathogens, and presence or absence of aggressive H. pylori strains. Gastrointestinal epithelial cells express several Toll-like receptors and determine the first defensive line against pathogens, and have been also described as mediators of tumorigenesis. However, other molecules, such as cytokines related to inflammation and innate immunity, including immune checkpoint molecules, interferon-gamma pathway and NETosis have been associated with an increased risk of GC. Therefore, this review will explore innate immune activation in the context of premalignant lesions of the gastric epithelium and established gastric tumors.

Metabolomic and biochemical analysis of mesocarp tissues from table grape berries with contrasting firmness reveals cell wall modifications associated to harvest and cold storage.

Tissue texture influences the grape berry consumers acceptance. We studied the biological differences between the inner and outer mesocarp tissues in hard and soft berries of table grapes cv NN107. Texture analysis revealed lower levels of firmness in the inner mesocarp as compared with the outer tissue. HPAEC-PAD analysis showed an increased abundance of cell wall monosaccharides in the inner mesocarp of harder berries at harvest. Immunohistochemical analysis displayed differences in homogalacturonan methylesterification and cell wall calcium between soft and hard berries. This last finding correlated with a differential abundance of calcium measured in the alcohol-insoluble residues (AIR) of the inner tissue of the hard berries. Analysis of abundance of polar metabolites suggested changes in cell wall carbon supply precursors, providing new clues in the identification of the biochemical factors that define the texture of the mesocarp of grape berries.

Generation of Chloroplast Molecular Markers to Differentiate Sophora toromiro and Its Hybrids as a First Approach to Its Reintroduction in Rapa Nui (Easter Island).

Sophora toromiro is an endemic tree of Rapa Nui with religious and cultural relevance that despite being extinct in the wild, still persists in botanical gardens and private collections around the world. The authenticity of some toromiro trees has been questioned because the similarities among hybrid lines leads to misclassification of the species. The conservation program of toromiro has the objective of its reinsertion into Rapa Nui, but it requires the exact genotyping and certification of the selected plants in order to efficiently reintroduce the species. In this study, we present for the first time the complete chloroplast genome of S. toromiro and four other Sophora specimens, which were sequenced de-novo and assembled after mapping the raw reads to a chloroplast database. The length of the chloroplast genomes ranges from 154,239 to 154,473 bp. A total of 130-143 simple sequence repeats (SSR) loci and 577 single nucleotide polymorphisms (SNPs) were identified.

Cell wall and metabolite composition of sweet cherry fruits from two cultivars with contrasting susceptibility to surface pitting during storage.

Surface pitting is a serious postharvest physiological disorder in sweet cherries that is observed as skin depressions developed days after bruising. This work aims to compare two cultivars displaying different pitting susceptibilities ('Kordia': relatively resistant; 'Sweetheart': relatively susceptible) using metabolomics profiling and cell wall sugar characterization at different developmental stages and during postharvest storage. Kordia was significantly firmer than Sweetheart, with 1.4-fold more alcohol-insoluble residues (AIRs). A significant correlation was observed between AIRs and deformation, indicating that the highest yields of cell wall material are positively correlated with the resistance to rupture. Additionally, free d-galacturonic acid was higher in pitted Sweetheart samples, likely indicating greater pectin degradation in this susceptible cultivar. Higher contents of the p-coumaric acid derivatives L-5-oxoproline and d-galactose in Sweetheart cherries were found. The metabolic changes during storage and cell wall composition could influence the susceptibility to surface pitting.

Cell wall and metabolite composition of berries of Vitis vinifera (L.) cv. Thompson Seedless with different firmness.

Firm berries are highly appreciated by table grape consumers. Cell wall composition is one of the main factors influencing the firmness of table grape berries. Nevertheless, the biological factors driving changes in berry firmness remain unclear. In the present work, we evaluated the firmness of berries of Vitis vinifera cv. Thompson Seedless. We selected two orchards displaying contrasting berry firmness and evaluated polar metabolites and cell wall composition. Our results suggest that berries from the soft orchard exhibited a higher accumulation of sugars at veraison whereas berries from the hard orchard accumulated the same sugars at harvest plus a higher amount of glucose monosaccharide at the cell wall. Thus, this study opens new insights about a connection between metabolic and cell wall changes with fruit firmness in a table grape variety, suggesting that it is possible to use metabolomic tools to identify metabolic biomarkers associated with table grape berry firmness.

Changes in cell wall pectins and their relation to postharvest mesocarp softening of "Hass" avocados (Persea americana Mill.).

The avocado is a climacteric fruit and begins a softening process after harvest. During ripening, the mesocarp changes in texture, and this affects fruit quality and cold storage capacity. Softening is commonly associated with cell wall disassembly in climacteric fruits. However, changes in the cell wall structure and composition during avocado softening are poorly understood. To understand this process, cell wall pectins in "Hass" avocado fruit were studied during ripening at 20 °C after harvest and after cold storage. Additionally, avocados were treated with 1-MCP to evaluate the delay in softening. Biochemical analysis showed a decrease in galacturonic acid (GalA) in alcohol-insoluble residues (AIR) and water-soluble pectin concomitant to softening, paralleled by an increase in polygalacturonase (PG) activity. In the same way, the ß-galactosidase activity increased in soft avocado fruit, along with a reduction in galactose in cell wall material and the Na2CO3-soluble fraction. The arabinose content in the cell wall material did not change during softening. However, there was a change in arabinose ratios between the different fractions of pectin, mainly in the fractions soluble in water and in Na2CO3. The cold storage of avocado fruit did not induce softening of the fruit, but the content of GalA showed a substantial decrease, accompanied by an increase in PG activity. Thus, our work supports the hypothesis that the solubilization of neutral sugars such as arabinose and rhamnose, as well as the loss of galactose content mediated by the enzyme ß-galactosidase, were the main factors that began the coordinated action of cell wall remodeling enzymes that resulted in the loss of firmness of avocado fruit.

UUAT1 Is a Golgi-Localized UDP-Uronic Acid Transporter That Modulates the Polysaccharide Composition of Arabidopsis Seed Mucilage.

UDP-glucuronic acid (UDP-GlcA) is the precursor of many plant cell wall polysaccharides and is required for production of seed mucilage. Following synthesis in the cytosol, it is transported into the lumen of the Golgi apparatus, where it is converted to UDP-galacturonic acid (UDP-GalA), UDP-arabinose, and UDP-xylose. To identify the Golgi-localized UDP-GlcA transporter, we screened Arabidopsis thaliana mutants in genes coding for putative nucleotide sugar transporters for altered seed mucilage, a structure rich in the GalA-containing polysaccharide rhamnogalacturonan I. As a result, we identified UUAT1, which encodes a Golgi-localized protein that transports UDP-GlcA and UDP-GalA in vitro. The seed coat of uuat1 mutants had less GalA, rhamnose, and xylose in the soluble mucilage, and the distal cell walls had decreased arabinan content. Cell walls of other organs and cells had lower arabinose levels in roots and pollen tubes, but no differences were observed in GalA or xylose contents. Furthermore, the GlcA content of glucuronoxylan in the stem was not affected in the mutant. Interestingly, the degree of homogalacturonan methylation increased in uuat1 These results suggest that this UDP-GlcA transporter plays a key role defining the seed mucilage sugar composition and that its absence produces pleiotropic effects in this component of the plant extracellular matrix.

Comparative study of two table grape varieties with contrasting texture during cold storage.

Postharvest softening of grape berries is one of the main problems affecting grape quality during export. Cell wall disassembly, especially of pectin polysaccharides, has been commonly related to fruit softening, but its influence has been poorly studied in grapes during postharvest life. In order to better understand this process, the Thompson seedless (TS) variety, which has significantly decreased berry texture after prolonged cold storage, was compared to NN107, a new table grape variety with higher berry firmness. Biochemical analysis revealed a greater amount of calcium in the cell wall of the NN107 variety and less reduction of uronic acids than TS during cold storage. In addition, the activity of polygalacturonase was higher in TS than NN107 berries; meanwhile pectin methylesterase activity was similar in both varieties. Polysaccharide analysis using carbohydrate gel electrophoresis (PACE) suggests a differential pectin metabolism during prolonged cold storage. Results revealed lower pectin fragments in TS after 60 days of cold storage and shelf life (SL) compared to 30 days of cold storage and 30 + SL, while NN107 maintained the same fragment profile across all time points evaluated. Our results suggest that these important differences in cell wall metabolism during cold storage could be related to the differential berry firmness observed between these contrasting table grape varieties.