Engineering production of antihypertensive peptides in plants

To date, a number of antihypertensive peptides (AHPs) have been identified. Most of these are derived from proteins present in common edible consumables, including milk, egg, and plant foods. Consumption of these foods serves as means of AHP delivery and thus contributing favorable health benefits. It is hypothesized that food crops, either over-expressing AHP precursor proteins or producing particular peptides as heterologous components, may serve as viable vehicles for production and delivery of functional foods as alternative hypertension therapies. In recent years, genetic engineering efforts have been undertaken to add value to functional foods. Pioneering approaches have been pursued in several crop plants, such as rice and soybean. In this review, a summary of current tools used for discovery of new AHPs, as well as strategies and perspectives of capitalizing on these AHPs in genetic engineering efforts will be presented and discussed. The implications of these efforts on the development of functional foods for preventing and treating hypertension are also presented.     

Deforestation and Reforestation of Latin America and the Caribbean (2001–2010)

Forest cover change directly affects biodiversity, the global carbon budget, and ecosystem function. Within Latin American and the Caribbean region (LAC), many studies have documented extensive deforestation, but there are also many local studies reporting forest recovery. These contrasting dynamics have been largely attributed to demographic and socio‐economic change. For example, local population change due to migration can stimulate forest recovery, while the increasing global demand for food can drive agriculture expansion. However, as no analysis has simultaneously evaluated deforestation and reforestation from the municipal to continental scale, we lack a comprehensive assessment of the spatial distribution of these processes. We overcame this limitation by producing wall‐to‐wall, annual maps of change in woody vegetation and other land‐cover classes between 2001 and 2010 for each of the 16,050 municipalities in LAC, and we used nonparametric Random Forest regression analyses to determine which environmental or population variables best explained the variation in woody vegetation change. Woody vegetation change was dominated by deforestation (?541,835 km²), particularly in the moist forest, dry forest, and savannas/shrublands biomes in South America. Extensive areas also recovered woody vegetation (+362,430 km²), particularly in regions too dry or too steep for modern agriculture. Deforestation in moist forests tended to occur in lowland areas with low population density, but woody cover change was not related to municipality‐scale population change. These results emphasize the importance of quantitating deforestation and reforestation at multiple spatial scales and linking these changes with global drivers such as the global demand for food.     

Pollen biology in four Mediterranean Quercus species

Potential pollen production, viability and germination were studied in the most important species of Quercus in the mountains of Córdoba to determine the contribution of each species to the total amount of airborne pollen. The results were compared over two consecutive years with different rainfall patterns. The viability of pollen grains was determined at anther opening, and during the pollination period, in order to determine potential pollination capacity. Results indicated that there were differences in the number of pollen grains produced by stamen in the four species. Equally, there were differences in the number of flowers among the species, being Q. suber the species with higher number of catkins groups and flowers per individual tree. Total pollen production per tree can be summarized in the following proportion: 1: 3: 3: 6 (Q. coccifera, Q. ilex ssp. ballota, Q. faginea and Q. suber). Potential pollen viability was estimated using the Fluorochromatic Reaction (FCR) and a germination assay. The results have shown that Quercus potential pollen viability is high and declines slowly with time. Q. coccifera was the species with the highest percentage of germination, with Q. suber being the lowest.     

27-Nor-Δ4-dafachronic acid is a synthetic ligand of Caenorhabditis elegans DAF-12 receptor

27-Nor-Δ⁴-dafachronic acid was prepared in nine steps and 14% overall yield by two sequential 2-carbon homologations from 20β-carboxyaldehyde-4-pregnen-3-one. Its activity was evaluated in vivo, where it rescued the Mig phenotype of daf-9(rh50) Caenorhabditis elegans mutants and restored their normal resistance to oxidative stress. 27-Nor-Δ⁴-dafachronic acid was also able to directly bind and activate DAF-12 in a transactivation cell-based luciferase reporter assay, although it was less active than the corresponding 25R-and 25S dafachronic acids. The binding mode of the 27-Nor steroid was studied by molecular dynamics using a homology model of the CeDAF-12 receptor.     

Diversity and expression of P450 genes from Dendroctonus valens LeConte (Curculionidae: Scolytinae) in response to different kairomones

Bark beetles (Curculionidae: Scolytinae) are major cause of woody plants death in the world. They colonize the stem and other parts of trees recognizing host-produced specific compounds (kairomones) and insect pheromones. Bark beetle's antennae and alimentary canal participate in the host selection identifying chemical compounds produced by trees and insects, and also in the metabolism and detoxification of these compounds. The red turpentine beetle (RTB), Dendroctonus valens LeConte, is an unaggressive species that colonize > 40 pine species (Pinaceae) in North and Central America. Several studies suggest that bark beetle cytochrome P450 enzymes are involved in monoterpene oxidation. In this study we identified by means of PCR, cloning, sequencing, and bioinformatic analysis, eleven full-length genes: five CYP4, four CYP6, and two CYP9 in the antennae and gut region of RTB, after stimulation with vapors of monoterpenes: (±)-α-pinene, (R)-(+)-α-pinene, (S)-(?)-β-pinene, (S)-(?)-α-pinene and (+)-3-carene; pine trees volatiles used by RTB as kairomones. The recovered cDNA of these genes vary from 1.5 kb to 1.8 kb and the open frame encodes from 496 to 562 amino acid proteins. The bioinformatic analysis suggests that the majority of P450 proteins encoded by these genes are membrane anchored in the endoplasmic reticulum. RT-qPCR assays showed differential expression of all CYP genes between male and female. The gene expression was dependent of monoterpenes and exposure time, with some of them sex, antennae and gut region specific. Significant differences among monoterpenes, gut region, antennae and exposure time were found. Our results suggest that some of these genes may be involved in the detoxification process of these compounds during tree colonization.     

Antioxidant and prebiotic effects of dietary fiber co-travelers from sugar Kombu in healthy rats

The edible brown seaweed sugar Kombu (Saccharina latissima) is a good source of dietary fiber (DF) and associated compounds. Besides it presents antioxidant capacity in vitro due to their sulfated polysaccharides and polyphenols. The effect of a DF-rich sugar Kombu diet on biochemical parameters and antioxidant and prebiotic effects in healthy rats was evaluated. Thus, rats were fed either a basal diet or a supplemented one with 10 % sugar Kombu for 4 weeks. Several health-promoting effects were found such as a decrease in triglycerides (TGL) and uric acid (UrA), and an increase in antioxidant status both in serum and cecum. Regarding prebiotic effect, higher cecum weight and total short chain fatty acid (SCFA) content were evidenced in the seaweed-fed group, without significant differences on total bacterial count of feces. Sugar Kombu and sulfated polysaccharides from its DF could be used as functional ingredients for further nutraceutical applications.     

The ALK-1/Smad1 pathway in cardiovascular physiopathology. A new target for therapy?

Activin receptor-like kinase-1 or ALK-1 is a type I cell surface receptor for the transforming growth factor-β (TGF-β) family of proteins. The role of ALK-1 in endothelial cells biology and in angiogenesis has been thoroughly studied by many authors. However, it has been recently suggested a possible role of ALK-1 in cardiovascular homeostasis.ALK-1 is not only expressed in endothelial cells but also in smooth muscle cells, myofibroblast, hepatic stellate cells, chondrocytes, monocytes, myoblasts, macrophages or fibroblasts, but its role in these cells have not been deeply analyzed. Due to the function of ALK-1 in these cells, this receptor plays a role in several cardiovascular diseases. Animals with ALK-1 haploinsufficiency and patients with mutations in Acvrl1 (the gene that codifies for ALK-1) develop type-2 Hereditary Hemorrhagic Telangiectasia. Moreover, ALK-1 heterozygous mice develop pulmonary hypertension. Higher levels of ALK-1 have been observed in atherosclerotic plaques, suggesting a possible protector role of this receptor. ALK-1 deficiency is also related to the development of arteriovenous malformations (AVMs). Besides, due to the ability of ALK-1 to regulate cell proliferation and migration, and to modulate extracellular matrix (ECM) protein expression in several cell types, ALK-1 has been now demonstrated to play an important role in cardiovascular remodeling.In this review, we would like to offer a complete vision of the role of ALK-1 in many process related to cardiovascular homeostasis, and the involvement of this protein in the development of cardiovascular diseases, suggesting the possibility of using the ALK-1/smad-1 pathway as a powerful therapeutic target.