Effect of curcumin-nanoemulsion associated with photodynamic therapy in breast adenocarcinoma cell line

Curcumin, a natural compound has several antineoplastic activities and is a promising natural photosensitizer used in photodynamic therapy. However, its low solubility in physiological medium limit the clinical use of curcumin. This study aimed to analyze the action of curcumin-nanoemulsion, a new and well-designed Drug Delivery System (DDS+) molecule, used as a photosensitizing agent in photodynamic therapy in an in vitro breast cancer model, MCF-7 cells. The empty nanoemulsion fulfils all necessary requirements to be an excellent DDS. Furthermore, the use of curcumin-nanoemulsion in photodynamic therapy resulted in a high phototoxic effect after activation at 440?nm, decreasing to <10% viable tumor cells after two irradiations and increasing the reactive oxygen species (ROS) production. The use of curcumin-nanoemulsion associated with photodynamic therapy resulted in an increase in the levels of caspase 3/7 activity for the studied MCF-7 cell model, indicating that this therapy triggers a cascade of events that lead to cell death, such as cellular apoptosis. In conclusion, curcumin-nanoemulsion proved to be efficient as a photosensitizing agent, had phototoxic effects, significantly decreased the proliferation of MCF-7 cells and stimulating the ROS production in combination with photodynamic therapy, so, this formulation has a great potential for use in treatment of breast cancer.     

Spatially Distinct Pools of TORC1 Balance Protein Homeostasis

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Identification of flavonoids as regulators of YbeY activity in Liberibacter asiaticus

Liberibacter asiaticus is the prevalent causative pathogen of Huanglongbing or citrus greening disease, which has resulted in a devastating crisis in the citrus industry. A thorough understanding of this pathogen's physiology and mechanisms to control cell survival is critical in the identification of therapeutic targets. YbeY is a highly conserved bacterial RNase that has been implicated in multiple roles. In this study, we evaluated the biochemical characteristics of the L. asiaticus YbeY (CLIBASIA_01560) and assessed its potential as a target for antimicrobials. YbeY_Las was characterized as an endoribonuclease with activity on 3′ and 5′ termini of 16S and 23S rRNAs, and the capacity to suppress the E. coli ΔybeY phenotype. We predicted the YbeY_Las protein:ligand interface and subsequently identified a flavone compound, luteolin, as a selective inhibitor. Site-directed mutagenesis was subsequently used to identify key residues involved in the catalytic activity of YbeY_Las. Further evaluation of naturally occurring flavonoids in citrus trees indicated that both flavones and flavonols had potent inhibitory effects on YbeY_Las. Luteolin was subsequently examined for efficacy against L. asiaticus in Huanglongbing-infected citrus trees, where a significant reduction in L. asiaticus gene expression was observed.     

High throughput measure of diversity in cytoplasmic and nuclear traits for unravelling geographic distribution of rosemary

In the present work, variability of both cytoplasmic and nuclear microsatellite traits was investigated with the aim of characterizing a set of rosemary germplasm resources (Salvia rosmarinus). Most of the materials were collected in Italy and France. High‐resolution melting curves were compared each other computing their Euclidean distances and estimating the differences within their principal component as a measure of genetic diversity. Mantel correlation results combined to linear discriminant analysis allowed examined populations to be divided in four principal groups corresponding to four geographic areas, with few interesting and discussed exceptions. As rosemary propagates by seeds coming from insect mediated pollination, steady wild populations can be expected to be in panmictic equilibrium. Gained results confirmed and extended precedent characterization of rosemary genotypes and are compatible with the distribution of other Mediterranean species, as well as with the presence of a glacial refugium in the north‐east area of Sardinia previously described. As the officinal use of this aromatic shrub is spreading, characterization and conservation of wild Mediterranean germplasm is gaining strategic importance. A core collection of 100 genotypes was pointed out as suitable for a cheaper biodiversity ex situ preservation as well as for subsequent metabolic and linkage disequilibrium analyses.     

Grassland harvesting alters ant community trophic structure: An isotopic study in tallgrass prairies

Disturbances have long been recognized as important forces for structuring natural communities but their effects on trophic structure are not well understood, particularly in terrestrial systems. This is in part because quantifying trophic linkages is a challenge, especially for small organisms with cryptic feeding behaviors such as insects, and often relies on conducting labor‐intensive feeding trials or extensive observations in the field. In this study, we used stable isotopes of carbon and nitrogen to examine how disturbance (annual biomass harvesting) in tallgrass prairies affected the trophic position, trophic range, and niche space of ants, a widespread grassland consumer. We hypothesized that biomass harvest would remove important food and nesting resources of insects thus affecting ant feeding relationships and trophic structure. We found shifts in the feeding relationships inferred by isotopic signatures with harvest. In particular, these shifts suggest that ants within harvest sites utilized resources at lower trophic levels (possibly plant‐based resources or herbivores), expanded trophic breadth, and occupied different niche spaces. Shifts in resource use following harvest could be due to harvest‐mediated changes in both the plant and arthropod communities that might affect the strength of competition or alter plant nitrogen availability. Because shifts in resource use alter the flow of nutrients across the food web, disturbance effects on ants could have ecosystem‐level consequences through nutrient cycling.     

Human chromosomal bands: nested structure,high-definition map and molecular basis

In this paper, we report investigations on the nested structure, the high-definition mapping, and the molecular basis of the classical Giemsa and Reverse bands in human chromosomes. We found the rules according to which the approximately 3,200 isochores of the human genome are assembled in high (850-band) resolution bands, and the latter in low (400-band) resolution bands, so forming the nested mosaic structure of chromosomes. Moreover, we identified the borders of both sets of chromosomal bands at the DNA sequence level on the basis of our recent map of isochores, which represent the highest-resolution, ultimate bands. Indeed, beyond the 100-kb resolution of the isochore map, the guanine and cytosine (GC) profile of DNA becomes turbulent owing to the contribution of specific sequences such as exons, introns, interspersed repeats, CpG islands, etc. The isochore-based level of definition (100 kb) of chromosomal bands is much higher than the cytogenetic definition level (2-3 Mb). The major conclusions of this work concern the high degree of order found in the structure of chromosomal bands, their mapping at a high definition, and the solution of the long-standing problem of the molecular basis of chromosomal bands, as these could be defined on the basis of compositional DNA properties alone.     

Gametogenesis of intergroup hybrids of hemiclonal frogs

European water frog hybrids Rana esculenta (R. ridibundaxR. lessonae) reproduce hemiclonally, by hybridogenesis: in the germ line they exclude the genome of one parental species and produce haploid gametes with an unrecombined genome of the other parental species. In the widespread L-E population system, both sexes of hybrids (E) coexist with R. lessonae (L). They exclude the lessonae genome and produce ridibunda gametes. In the R-E system, hybrid males coexist with R. ridibunda (R); they exclude either their ridibunda or their lessonae genome and produce sperm with a lessonae or with a ridibunda genome or a mixture of both kinds of sperm. We examined 13 male offspring, 12 of which were from crosses between L-E system and R-E system frogs. All were somatically hybrid. With one exception, they excluded the lessonae genome in the germ line and subsequently endoreduplicated the ridibunda genome. Spermatogonial metaphases contained a haploid or a diploid number of ridibunda chromosomes, identified through in situ hybridization to a satellite DNA marker, and by spermatocyte I metaphases containing a haploid number of ridibunda bivalents. The exception, an F1 hybrid between L-E system R. lessonae and R-E system R. ridibunda, was not hybridogenetic, showed no genome exclusion, and evidenced a disturbed gametogenesis resulting from the combination of two heterospecific genomes. None of the hybridogenetic hybrids showed any cell lines excluding the ridibunda genome, the pattern most frequent in hybrids of the R-E system, unique to that system, and essential for its persistence. A particular combination of R-E system lessonae and R-E system ridibunda genomes seems necessary to induce the R-E system type of hemiclonal gametogenesis.