Entorno inflamatorio diferencial en pacientes con osteoporosis y diabetes mellitus tipo 2 / Differential inflammatory environment in patients with osteoporosis and type 2 diabetes mellitus

Objetivo: La diabetes mellitus tipo 2 (DM2) y la osteoporosis son enfermedades asociadas con un entorno pro-inflamatorio, cuya prevención mediante nuevas estrategias terapéuticas podría evitar su desarrollo. Sin embargo, existe un escaso número de estudios que evalúen el perfil inflamatorio de la osteoporosis en pacientes con DM2.El objetivo de este estudio se centró en evaluar la respuesta inflamatoria inmunitaria mediante concentraciones séricas de nueve citocinas, dos de ellas de carácter anti-inflamatorio (IL-10, IL-5) y seis pro-inflamatorias (IL-2, IL-6, IL-12 (p70), IL-17A, TNFα e IFNɣ) en 163 individuos con DM2 y 47 controles. Una subpoblación, formada por 43 pacientes DM2 sin osteoporosis, y 33 con osteoporosis, fue analizada en más profundidad a nivel de parámetros óseos. Además, hemos evaluado las hormonas calciotropas, los marcadores de remodelado óseo, densidad mineral ósea y fracturas vertebrales en la población, y hemos analizado la relación de las citocinas ensayadas con la DM2, la osteoporosis y las fracturas vertebrales prevalentes.Los pacientes con DM2 tenían concentraciones séricas significativamente más altas de IL-10 en comparación con el grupo control (0,5±1 vs. 0,14±0,3 pg/ml; p=0,016) y los niveles de IL-12 p70 se mostraron más bajos en pacientes con DM2 respecto a los controles (2,9±1,6 vs. 3,9±3,1 pg/ml; p=0,027).En el grupo de pacientes con DM2 y osteoporosis, los niveles de la citocina IL-6 resultaron elevados respecto al grupo de DM2 sin osteoporosis (10,9±14,6 vs. 4,5±7,0; p=0,017). También se observó una asociación de IL-5, siendo sus niveles más bajos en el grupo DM2 con osteoporosis (1,7±0,2 vs. 3,8±0,6; p=0,032). Además, la IL-5 mostró una correlación directa con los niveles del biomarcador de formación ósea fosfatasa alcalina ósea (r=0,277, p=0,004) en la subpoblación de pacientes con DM2. El resto de citocinas no mostraron diferencias significativas. (AU)

Ole e 13 is the unique food allergen in olive: Structure-functional, substrates docking, and molecular allergenicity comparative analysis.

Thaumatin-like proteins (TLPs) are enzymes with important functions in pathogens defense and in the response to biotic and abiotic stresses. Last identified olive allergen (Ole e 13) is a TLP, which may also importantly contribute to food allergy and cross-allergenicity to pollen allergen proteins. The goals of this study are the characterization of the structural-functionality of Ole e 13 with a focus in its catalytic mechanism, and its molecular allergenicity by extensive analysis using different molecular computer-aided approaches covering a) functional-regulatory motifs, b) comparative study of linear sequence, 2-D and 3D structural homology modeling, c) molecular docking with two different ß-D-glucans, d) conservational and evolutionary analysis, e) catalytic mechanism modeling, and f) IgE-binding, B- and T-cell epitopes identification and comparison to other allergenic TLPs. Sequence comparison, structure-based features, and phylogenetic analysis identified Ole e 13 as a thaumatin-like protein. 3D structural characterization revealed a conserved overall folding among plants TLPs, with mayor differences in the acidic (catalytic) cleft. Molecular docking analysis using two ß-(1,3)-glucans allowed to identify fundamental residues involved in the endo-1,3-ß-glucanase activity, and defining E84 as one of the conserved residues of the TLPs responsible of the nucleophilic attack to initiate the enzymatic reaction and D107 as proton donor, thus proposing a catalytic mechanism for Ole e 13. Identification of IgE-binding, B- and T-cell epitopes may help designing strategies to improve diagnosis and immunotherapy to food allergy and cross-allergenic pollen TLPs.

Olive pollen profilin (Ole e 2 allergen) co-localizes with highly active areas of the actin cytoskeleton and is released to the culture medium during in vitro pollen germination.

Pollen allergens offer a dual perspective of study: some of them are considered key proteins for pollen physiology, but they are also able to trigger allergy symptoms in susceptible humans after coming in contact with their tissues. Profilin (Ole e 2 allergen) has been characterized, to some extent, as one of the major allergens from Olea europaea L. pollen, a highly allergenic species in the Mediterranean countries. In order to obtain clues regarding the biological role of this protein, we have analyzed both its cellular localization and the organization of actin throughout pollen hydration and early pollen tube germination. The localization of the cited proteins was visualized by confocal laser scanning microscopy immunofluorescence using different antibodies. Upon pollen hydration and pollen germination, a massive presence of profilin was detected close to the site of pollen tube emergence, forming a ring-like structure around the 'effective' apertural region. Profilin was also detected in the pollen exine of the germinating pollen grains and in the germination medium. After using a permeabilization-enhanced protocol for immunolocalization, profilin was also localized in the cytoplasm of the pollen tube, particularly at both the proximal and apical ends. Noticeable accumulations of actin were observed in the cytoplasm of the pollen tube; particularly, in both the apical region and the area immediately close to the aperture. Actin filaments were not observed, probably due to the need of further enhanced fixation procedures. The ultrastructural localization of profilin showed the presence of the protein in the cytoplasm of both the mature pollen grain and the pollen tube. The results shown here could be interpreted as signs of a massive dissociation of the actin-profilin complexes, mobilization of actin monomers, and therefore, an intense activity of the actin cytoskeleton. The extensive release of allergenic proteins from the pollen grain into the surrounding aqueous media, as described here for profilin, may help us to understand the mechanisms by which these allergens might come in contact with the human mucosa, therefore triggering the symptoms of allergy.

Differential characteristics of olive pollen from different cultivars: biological and clinical implications.

The olive tree is grown in many parts of the world. Its germplasm is very broad, with 250 varieties in Spain alone. Variations in the ability of pollen to germinate have been studied in detail and show conspicuous differences between varieties. However, commercial olive pollen from cultivars whose origin is unknown is the material that is commonly used for clinical and biological studies. We aim to assess the putative heterogeneity of olive cultivars with regard to the presence of several pollen allergens and to determine whether these differences have biological and clinical relevance. Previous studies show that most allergens isolated and characterized to date are highly polymorphic. Olive cultivars display wide differences in the expression levels of many allergens and in the number and molecular characteristics of the allergen isoforms expressed. These differences are maintained over the years, and are intrinsic to the genetics of each cultivar. Such broad polymorphism seems to be involved in the physiology of the olive reproductive system, which might include the adaptation of the plant to different environmental conditions, the establishment of the compatibility system, and pollen performance. The differences in allergen composition in cultivars, particularly in the Ole e 1 allergen, are responsible for the important differences in the allergenic potency of the extracts. These findings could have a number of implications for the diagnosis and therapy of olive pollen allergy. We discuss how cultivar differences affect extract quality, diagnostic and therapeutic efficacy and safety, and the development of new vaccines based on the use of recombinant allergens.