Immunomodulatory Properties of Polysaccharides from the Coral Pseudopterogorgia americana in Macrophages

Polysaccharides from marine organisms produce an important regulatory effect on the mammalian immune system. In this study, the immunomodulatory properties of a polysaccharide that was isolated from the coral Pseudopterogorgia americana (PPA) were investigated. PPA increased the expression levels of tumour necrosis factor-α (TNF-α), interleukin-6 (IL-6) and cyclooxygenase-2 (COX-2), but not inducible nitric oxide synthase and nitric oxide, in macrophages. A mechanistic study revealed that PPA activated macrophages through the toll-like receptor-4 and induced the generation of reactive oxygen species (ROS), increased the phosphorylation levels of protein kinase C (PKC)-α, PKC-δ and mitogen-activated protein kinases (MAPK), and activated NF-κB. The inhibition of ROS and knockdown of PKC-α reduced PPA-mediated TNF-α and IL-6 expression; however, the knockdown of PKC-δ significantly increased PPA-mediated TNF-α expression. In addition, the inhibition of c-Jun N-terminal kinase-1/2 and NF-κB reduced PPA-mediated TNF-α, IL-6 and COX-2 expression. Furthermore, the inhibition of ROS, MAPK and PKC-α/δ reduced PPA-mediated NF-κB activation, indicating that ROS, MAPK and PKC-α/δ function as upstream signals of NF-κB. Finally, PPA treatment decreased the phagocytosis activity of macrophages and reduced cytokine expression in bacteria-infected macrophages. Taken together, our current findings suggest that PPA can potentially play a role in the development of immune modulators in the future.

COMPOSICIÓN Y ESTRUCTURA DE LA COMUNIDAD DE OCTOCORALES EN LOS BAJOS DE SANCHO PARDO, ARRECIFE DE LOS COLORADOS, CUBA

Se estudiaron la composición y estructura de las comunidades de octocorales en cinco sitios localizados en los Bajos de Sancho Pardo (arrecife de Los Colorados (NW Cuba) en agosto del 2010. Se empleó como unidad de muestreo un marco cuadrado de un metro de lado. En total se estudiaron 11 zonas del arrecife frontal, dos zonas traseras y una cresta. Se identificaron 34 especies de gorgonias de 2687 colonias. En el arrecife frontal, Pseudopterogorgia americana y Pseudopterogorgia elisabethae fueron las especies dominantes, mientras que en la zona trasera lo hicieron Briareum asbestinum y Pseudopterogorgia bipinnata. En la cresta arrecifal predominaron Gorgonia ventalina y Plexaura homomalla. Se encontraron diferencias significativas (P = 0.05) para la densidad de gorgonias entre localidades del arrecife frontal. Los resultados de los índices de heterogeneidad y de equitatividad permiten inferir que un 79% de las localidades se correspondieron con ambientes favorables o muy favorables y el 64% indicaron ambientes constantes o casi constantes. En el 79% de las localidades se infirió una tensión hidrodinámica baja y en el resto resultó entre moderada y alta en zonas someras de la cresta y el arrecife frontal. El estado general de la comunidad de octocorales fue bueno según los valores de densidad y abundancia de especies registrados, aunque se evidencia que en las zonas al oeste hay un mayor cubrimiento por macroalgas carnosas, que puede constituir un factor que limita el reclutamiento. ABSTRACTThe composition and structure of octocoral communities was studied in five locations in Bajos de Sancho Pardo (Los Colorados reefs (NW Cuba)) in August 2010. Quadrants measuring one square meter were used as sampling units. A total of 11 fore reefs, two rear zones and one reef crest were studied. Thirty-four species of gorgonians were identified in 2687 colonies. Predominant species included Pseudopterogorgia americana and Pseudopterogorgia elisabethae in the fore reef zone, Briareum asbestinum and Pseudopterogorgia bipinnata in the rear reef, and Gorgonia ventalina and Plexaura homomalla in the reef crest. Significant differences (P = 0.05) were found in the density of gorgonians between fore reef stations. Based on the results of the heterogeneity and evenness indexes, it can be inferred that 79% of the stations were consistent with favorable or very favorable environments and 64% with constant or nearly constant environments. Hydrodynamic stress was low in 79% of the stations, while it was moderate to high in shallow areas of the crest and fore reef. The overall condition of the octocoral community was good according to recorded values of species density and abundance, although it is evident that in the western areas there is greater coverage by fleshy macroalgae, which may be a limiting factor for growth.

COMPOSICIÓN DE LAS COMUNIDADES DE OCTOCORALES Y CORALES PÉTREOS Y LA INCIDENCIA DEL BLANQUEAMIENTO DEL 2005 EN JARDINES DE LA REINA, CUBA

En los años 2001 y 2005, se estudió la composición de las comunidades de octocorales y corales pétreos en el archipiélago de los Jardines de la Reina. Se analizó, en la comunidad de corales pétreos, la incidencia del blanqueamiento ocurrido en el 2005 en el Caribe. Para ello se establecieron doce estaciones de muestreo (siete en el arrecife frontal somero y cinco en el arrecife de cresta), en cada una de estas se estimó la densidad mediante el marco cuadrado de 1 m de lado. En el arrecife frontal somero se identificaron un total de 62 especies (26 de octocorales y 36 de corales), siendo las más abundantes: Pseudopterogorgia americana (2.4 colonias/m2), Eunicea flexuosa (1.1 colonias/m2), Siderastrea siderea (5.0 colonias/m2) y Agaricia agaricites (4.0 colonias/m2). En el arrecife de cresta se identificaron un total de 31 especies (13 de octocorales y 18 de corales), predominando: Briareum asbestinum (1.3 colonias/m2), Porites astreoides (2.5 colonias/m2) y Millepora complanata (1.0 colonias/m2). Las especies más sensibles al blanqueamiento fueron: A. agaricites , Millepora spp. y Montastraea annularis. En sentido general, dicho suceso tuvo una incidencia pobre sobre los corales pétreos. Es menester la ejecución de monitoreos al permitir ajustar los planes de manejo en función de los cambios que puedan ocurrir en la estructura de las comunidades bentónicas.ABSTRACT Octocoral and stony coral communities in the Jardines de la Reina archipelago (Cuba) were studied in 2001 and again in 2005. The incidence of the 2005 bleaching event in the Caribbean was analyzed in the stony coral community. Twelve sampling stations were established: seven in the shallow forereef and five in reef crests, with one square meter quadrants to estimate density. A total of 62 species (26 octocorals and 36 stony corals) were identified in the shallow forereef, including Pseudopterogorgia americana (2.4 colonies/m2), Eunicea flexuosa (1.1 colonies/m2), Siderastrea siderea (5.0 colonies/m2) and Agaricia agaricites (4.0 colonies/m2). In the reef crest, 31 species were identified (13 octocorals and 18 stony corals), with Briareum asbestinum (1.3 colonies/m2), Porites astreoides (2.5 colonies/m2) and Millepora complanata (1.0 colonies/m2) being the most abundant. The most sensitive species to bleaching were: A. agaricites, Millepora spp. and Montastraea annulariS. In general, this event showed a poor incidence with stony corals. Constant monitoring is necessary to adjust the management plan to the changes that may occur in the structure of the benthic communities.