RESUMO
Sponges are fundamental components of coral reef communities and, unfortunately, like other major benthic members, they too have been impacted by epizootic and panzootic events. We report on the prevalence of disease-like conditions affecting populations of the giant barrel sponge Xestospongia muta across shallow and mesophotic coral reefs off La Parguera Natural Reserve (LPNR) and Mona Island Marine Reserve (MIMR) in Puerto Rico. Four different conditions affecting X. muta were observed during our surveys, of which 3 have been previously reported: cyclic spotted bleaching (CSB; apparently non-lethal), Xestospongia-tissue wasting disease (X-TWD; apparently lethal), and sponge orange band disease (SOB; sparsely associated with X-TWD infected individuals). Additionally, we describe a fourth condition, Xestospongia-tissue hardening condition (X-THC), a previously unreported disease recently observed along the insular shelf margin off LPNR and MIMR. Within LPNR, a total of 764 specimens of X. muta were inspected and measured. Of these, 590 sponges (72.2%) had CSB, 25 (3.27%) had signs of X-TWD, 7 (0.92%) had SOB, and the remaining 142 (18.6%) were apparently healthy. Three colonies inhabiting upper mesophotic depths on the LPNR insular shelf showed signs of CSB and X-TWD. At MIMR, video-transect surveys revealed a total of 514 colonies, of which 40 (7.78%) had signs of CSB and/or XTWD, 14 (2.72%) were affected by X-THC, while the remaining 460 (89.5%) showed no external signs of disease and appeared healthy. The presence of 4 concomitant disease-like conditions in barrel sponges of Puerto Rico is alarming, and indicative of the deteriorating status of Caribbean coral reefs.
Assuntos
Antozoários , Xestospongia , Animais , Recifes de Corais , Ecossistema , Porto Rico/epidemiologiaRESUMO
Xestospongia muta is among the most emblematic sponge species inhabiting coral reefs of the Caribbean Sea. Besides being the largest sponge species growing in the Caribbean, it is also known to produce secondary metabolites. This study aimed to assess the effect of depth and season on the symbiotic bacterial dynamics and major metabolite profiles of specimens of X. muta thriving in a tropical marine biome (Portobelo Bay, Panamá), which allow us to determine whether variability patterns are similar to those reported for subtropical latitudes. The bacterial assemblages were characterized using Illumina deep-sequencing and metabolomic profiles using UHPLC-DAD-ELSD from five depths (ranging 9-28 m) across two seasons (spring and autumn). Diverse symbiotic communities, representing 24 phyla with a predominance of Proteobacteria and Chloroflexi, were found. Although several thousands of OTUs were determined, most of them belong to the rare biosphere and only 23 to a core community. There was a significant difference between the structure of the microbial communities in respect to season (autumn to spring), with a further significant difference between depths only in autumn. This was partially mirrored in the metabolome profile, where the overall metabolite composition did not differ between seasons, but a significant depth gradient was observed in autumn. At the phyla level, Cyanobacteria, Firmicutes, Actinobacteria, and Spirochaete showed a mild-moderate correlation with the metabolome profile. The metabolomic profiles were mainly characterized by known brominated polyunsaturated fatty acids. This work presents findings about the composition and dynamics of the microbial assemblages of X. muta expanding and confirming current knowledge about its remarkable diversity and geographic variability as observed in this tropical marine biome.
Assuntos
Bactérias/isolamento & purificação , Microbiota , Água do Mar/química , Xestospongia/microbiologia , Animais , Bactérias/classificação , Bactérias/genética , Fenômenos Fisiológicos Bacterianos , Biodiversidade , Região do Caribe , Recifes de Corais , Panamá , Filogenia , Estações do Ano , Água do Mar/microbiologia , Simbiose , Xestospongia/fisiologiaRESUMO
Fractionation of the bioactive CHCl3-MeOH (1:1) extracts obtained from two collections of the sponge consortium Plakortis symbiotica-Xestospongia deweerdtae from Puerto Rico provided two new plakinidone analogues, designated as plakinidone B (2) and plakinidone C (3), as well as the known plakinidone (1), plakortolide F (4), and smenothiazole A (5). The structures of 1-5 were characterized on the basis of 1D and 2D NMR spectroscopic, IR, UV, and HRMS analysis. The absolute configurations of plakinidones 2 and 3 were established through chemical correlation methods, VCD/ECD experiments, and spectroscopic data comparisons. When assayed in vitro against Mycobacterium tuberculosis H37Rv, none of the plakinidones 1-3 displayed significant activity, whereas smenothiazole A (5) was the most active compound, exhibiting an MIC value of 4.1 µg/mL. Synthesis and subsequent biological screening of 8, a dechlorinated version of smenothiazole A, revealed that the chlorine atom in 5 is indispensable for anti-TB activity.
Assuntos
Antituberculosos/farmacologia , Mycobacterium tuberculosis/química , Peróxidos/farmacologia , Plakortis/química , Tiazóis/síntese química , Tiazóis/farmacologia , Valina/análogos & derivados , Xestospongia/química , Animais , Antituberculosos/síntese química , Antituberculosos/química , Produtos Biológicos , Dioxinas/síntese química , Dioxinas/química , Dioxinas/farmacologia , Lactonas/síntese química , Lactonas/química , Lactonas/farmacologia , Espectroscopia de Ressonância Magnética , Estrutura Molecular , Mycobacterium tuberculosis/metabolismo , Peróxidos/síntese química , Peróxidos/química , Porto Rico , Tiazóis/química , Valina/síntese química , Valina/química , Valina/farmacologiaRESUMO
Plakortinic acids A (2) and B (3), two polyketide endoperoxides with a bicyclo[4.2.0]octene unit, were isolated as minor constituents from the sponge-sponge symbiotic association Plakortis halichondrioides-Xestospongia deweerdtae, along with known epiplakinic acid F (1). The structures of the mixture of two inseparable compounds were determined by spectroscopic analysis. Screening for cytotoxic activity of the mixture against two human tumor cell lines revealed that these compounds are very active at sub-micromolar concentration.
Assuntos
Peróxidos/química , Plakortis/química , Policetídeos/química , Xestospongia/química , Animais , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais/métodos , Humanos , Peróxidos/isolamento & purificação , Peróxidos/farmacologia , Policetídeos/isolamento & purificação , Policetídeos/farmacologia , EstereoisomerismoRESUMO
Cryptococcus gattii is a human pathogen and causative agent of a pernicious, sometimes fatal, disseminated fungal disease. Investigation of antifungal extracts of the marine sponge association Plakortis halichondrioides-Xestospongia deweerdtae and the sponge Plakortis zyggompha from the Bahamas led to the discovery and isolation of 6-epi-7,8-dihydroplakortide K (1), plakortide AA (2), and three new plakinic acids, N-P (4-6; unstable 1,2-dioxolanes bearing benzyl-substituted conjugated dienes), along with known plakinic acids L, K, and M.5 Chiroptical comparisons and DFT calculations of (13)C NMR chemical shifts were used to assign the absolute stereostructure of 4. The stereospecific base-promoted rearrangement-saponification of 1 to 10 was briefly investigated and showed tight kinetic control and stereospecific formation of the new C-2 stereocenter with inversion at C-3. Plakinic acid M and plakortides 9 and 11 exhibited antifungal activity against C. gattii (MIC90 = 2.4 to 36 µM), but plakinic acids N-P were inactive under the same conditions.
Assuntos
Antifúngicos/isolamento & purificação , Antifúngicos/farmacologia , Produtos Biológicos/isolamento & purificação , Produtos Biológicos/farmacologia , Cryptococcus gattii/química , Peróxidos/isolamento & purificação , Peróxidos/farmacologia , Plakortis/microbiologia , Xestospongia/microbiologia , Animais , Antifúngicos/química , Bahamas , Produtos Biológicos/química , Dioxanos/química , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Biologia Marinha , Testes de Sensibilidade Microbiana , Estrutura Molecular , Ressonância Magnética Nuclear Biomolecular , Peróxidos/química , Relação Estrutura-AtividadeRESUMO
Chemical analysis of the Chinese marine sponge Xestospongia testudinaria afforded a library of brominated polyunsaturated lipids including eight new compounds, named xestonarienes A-H (3-10) and thirteen known analogues (11-23). The structures of the new compounds were elucidated by detailed spectroscopic analysis and by comparison with literature data. The isolated lipids were evaluated for their inhibitory activity against pancreatic lipase (PL), an essential enzyme for efficient fat digestion and the major metabolite, 14, exhibited a marked inhibitory activity (IC50 = 3.11 µM), similar to that of the positive control Orlistat (IC50 = 0.78 µM). The preliminary structure-activity relationships on the series of compounds clearly evidenced that a terminal (E)-enyne functionality, a diyne within the chain, and methyl ester group are all key functional groups for the activity of this class of PL inhibitors. Further biological investigation on compound 14 revealed a significant decrease in the plasma triglyceride level following an oral lipid challenge in C57BLKS/J male mice. Acute toxicology study demonstrated that compound 14 was non-toxic up to 1600 mg/kg p.o in mice. This is the first report of the PL inhibitory activity for brominated polyunsaturated lipids and the obtained results qualify compound 14 as a potent and bioavailable drug candidate for a mild and safe treatment to prevent and reduce obesity.
Assuntos
Inibidores Enzimáticos/farmacologia , Ácidos Graxos Insaturados/farmacologia , Hidrocarbonetos Bromados/farmacologia , Lipase/antagonistas & inibidores , Lipídeos/farmacologia , Xestospongia/química , Animais , China , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/química , Inibidores Enzimáticos/isolamento & purificação , Ácidos Graxos Insaturados/química , Ácidos Graxos Insaturados/isolamento & purificação , Feminino , Hidrocarbonetos Bromados/química , Hidrocarbonetos Bromados/isolamento & purificação , Lipase/metabolismo , Lipídeos/química , Lipídeos/isolamento & purificação , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Estrutura Molecular , Pâncreas/enzimologia , Relação Estrutura-Atividade , SuínosRESUMO
The giant barrel sponge Xestospongiatestudinaria is an ecologically important species that is widely distributed across the Indo-Pacific. Little is known, however, about the precise biogeographic distribution and the amount of morphological and genetic variation in this species. Here we provide the first detailed, fine-scaled (<200 km(2)) study of the morphological and genetic composition of X. testudinaria around Lembeh Island, Indonesia. Two mitochondrial (CO1 and ATP6 genes) and one nuclear (ATP synthase ß intron) DNA markers were used to assess genetic variation. We identified four distinct morphotypes of X. testudinaria around Lembeh Island. These morphotypes were genetically differentiated with both mitochondrial and nuclear markers. Our results indicate that giant barrel sponges around Lembeh Island, which were all morphologically identified as X. testudinaria, consist of at least two different lineages that appear to be reproductively isolated. The first lineage is represented by individuals with a digitate surface area, CO1 haplotype C5, and is most abundant around the harbor area of Bitung city. The second lineage is represented by individuals with a predominantly smooth surface area, CO1 haplotype C1 and can be found all around Lembeh Island, though to a lesser extent around the harbor of Bitung city. Our findings of two additional unique genetic lineages suggests the presence of an even broader species complex possibly containing more than two reproductively isolated species. The existence of X. testudinaria as a species complex is a surprising result given the size, abundance and conspicuousness of the sponge.
Assuntos
Variação Genética , Fenótipo , Xestospongia/genética , Animais , Biodiversidade , Citocromos c1/genética , Genes Mitocondriais , Haplótipos , Filogenia , Filogeografia , Índias OcidentaisRESUMO
The aim of this study was to examine sponge orange band (SOB) disease affecting the prominent Caribbean sponge Xestospongia muta. Scanning and transmission electron microscopy revealed that SOB is accompanied by the massive destruction of the pinacoderm. Chlorophyll a content and the main secondary metabolites, tetrahydrofurans, characteristic of X. muta, were significantly lower in bleached than in healthy tissues. Denaturing gradient gel electrophoresis using cyanobacteria-specific 16S rRNA gene primers revealed a distinct shift from the Synechococcus/Prochlorococcus clade of sponge symbionts towards several clades of unspecific cyanobacteria, including lineages associated with coral disease (i.e. Leptolyngbya sp.). Underwater infection experiments were conducted by transplanting bleached cores into healthy individuals, but revealed no signs of SOB development. This study provided no evidence for the involvement of a specific microbial pathogen as an etiologic agent of disease; hence, the cause of SOB disease in X. muta remains unidentified.
Assuntos
Cianobactérias/fisiologia , Prochlorococcus/fisiologia , Synechococcus/fisiologia , Xestospongia/microbiologia , Animais , Bahamas , Clorofila/análise , Clorofila A , Cromatografia Líquida de Alta Pressão , Cianobactérias/classificação , Eletroforese em Gel de Gradiente Desnaturante , Florida , Furanos/análise , Microscopia Eletrônica de Varredura , Análise de Sequência de DNA , Espectrofotometria , Simbiose , Xestospongia/química , Xestospongia/fisiologia , Xestospongia/ultraestruturaRESUMO
An affinity matrix containing the antimalarial drug target Plm II (plasmepsin II) as ligand was generated. This enzyme belongs to the family of Plasmodium (malarial parasite) aspartic proteinases, known as Plms (plasmepsins). The procedure established to obtain the support has two steps: the immobilization of the recombinant proenzyme of Plm II to NHS (N-hydroxysuccinimide)-activated Sepharose and the activation of the immobilized enzyme by incubation at pH 4.4 and 37 degrees C. The coupling reaction resulted in a high percentage immobilization (95.5%), and the matrices obtained had an average of 4.3 mg of protein/ml of gel. The activated matrices, but not the inactive ones, were able to hydrolyse two different chromogenic peptide substrates and haemoglobin. This ability was completely blocked by the addition of the general aspartic-proteinase inhibitor, pepstatin A, to the reaction mixture. The matrices were useful in the affinity purification of the Plm II inhibitory activity detected in marine invertebrates, such as Xestospongia muta (giant barrel sponge) and the gorgonian (sea-fan coral) Plexaura homomalla (black sea rod), with increases of 10.2- and 5.9-fold in the specific inhibitory activity respectively. The preliminary K(i) values obtained, 46.4 nM (X. muta) and 1.9 nM (P. homomalla), and the concave shapes of the inhibition curves reveal that molecules are reversible tight-binding inhibitors of Plm II. These results validated the use of the affinity matrix for the purification of Plm II inhibitors from complex mixtures and established the presence of Plm II inhibitors in some marine invertebrates.