Physiological responses of Holothuria grisea during a wound healing event: An integrated approach combining tissue, cellular and humoral evidence.

Due to their tissue structure similar to mammalian skin and their close evolutionary relationship with chordates, holothurians (Echinodermata: Holothuroidea) are particularly interesting for studies on wound healing. However, previous studies dealing with holothuroid wound healing have had limited approaches, being restricted to tissue repair or perivisceral immune response. In this study, we combined tissue, cellular and humoral parameters to study the wound healing process of Holothuria grisea. The immune responses of the perivisceral coelom were assessed by analyzing the number, proportion and viability of coelomocytes and the volume and protein concentration of the coelomic fluid. Additionally, the morphology of the healing tissue and number of coelomocytes in the connective tissue of different body wall layers were examined over 30 days. Our results showed that perivisceral reactions started 3 h after injury and decreased to baseline levels within 24 h. In contrast, tissue responses were delayed, beginning after 12 h and returning to baseline levels only after day 10. The number of coelomocytes in the connective tissue suggests a potential cooperation between these cells during wound healing: phagocytes and acidophilic spherulocytes act together in tissue clearance/homeostasis, whereas fibroblast-like and morula cells cooperate in tissue remodeling. Finally, our results indicate that the major phases observed in mammalian wound healing are also observed in H. grisea, despite occurring at a different timing, which might provide insights for future studies. Based on these data, we propose a model that explains the entire healing process in H. grisea.

Effects of plasticizer Di(2-ethylhexyl) phthalate (DEHP) on the microbiome of the marine sponge Hymeniacidon heliophila.

Marine pollution research in the last 15 years focused on an emerging anthropogenic contaminant: plastic debris and more specifically, microplastics. Since, not only its physical impacts on marine invertebrates were studied, but also its additives. Phthalate, a plasticizer commonly found in the ocean and known endocrine disruptor was already observed in different aquatic invertebrates, but few is known about its presence and possible effects in Porifera physiology. Our study aimed to analyze potential shifts in Hymeniacidon heliophila (Desmosponge) microbiome after exposure to Di(2-ethylhexyl) phthalate (DEHP), the most common phthalate found in the ocean, in three different doses for 4 and 24 h. Results indicate that alpha diversity had significantly changed between control and exposed organisms but not in all multicomparisons. Microbial community structure changed after exposure as well although most abundant phyla did not vary along the experiment. The core microbiome between control and each exposed organisms contained the vast majority of total ASVs and a few ASVs were exclusive to each experimental group. After DEHP exposure, microbial classes had significant changes and species with phthalate degradation enzymes were identified in a specifically dose dependent manner pointing to a possible bacterial consortium responsible for the phthalate degradation. The bacterial detoxification activity may lead to H. heliophila resistance during DEHP exposure in polluted environmental conditions.

In Vivo Biological Effects of Marine Biosilica on a Tibial Bone Defect in Rats

Abstract Research on biomaterials of natural origin has gained prominence in the literature. Above all, marine sponges, due to their architecture and structural components, present a promising potential for the engineering of bone tissue. In vitro studies demonstrate that a biosilica of marine sponges has osteogenic potential. However, in vivo works are needed to elucidate the interaction of biosilica (BS) and bone tissue. The objective of the study was to evaluate the morphological and chemical characteristics of BS compared to Bioglass (BG) by scanning electron microscopy (SEM) and X-ray dispersive energy (EDX) spectroscopy. In addition, to evaluate the biological effects of BS, through an experimental model of tibial bone defect using histopathological, histomorphometric, immunohistochemical (IHC) and mechanical tests. SEM and EDX demonstrated the successful extraction of BS. Histopathological analysis demonstrated that Control Group (GC) had greater formation of newly formed bone tissue compared to BG and BS, yet BG bone neoformation was greater than BS. However, BS showed material degradation and granulation tissue formation, with absence of inflammatory process and formation of fibrotic capsule. The results of histomorphometry corroborate with those of histopathology, where it is worth emphasizing the positive influence of BS in osteoblastic activity. IHQ demonstrated positive VEGF and TGF-β immunoexpression for GC, BS and BG. In the mechanical test no significant differences were found. The present results demonstrate the potential of BS in bone repair, further studies are needed other forms of presentation of BS are needed.

Checklist de Porifera do Estado de São Paulo, Brasil / Checklist of Porifera from São Paulo State, Brazil

As esponjas (Filo Porifera) são um dos metazoários mais antigos existentes, mas ainda facilmente encontradas em uma grande variedade de ambientes aquáticos. São um componente fundamental em diversos ecossistemas, influenciando diretamente a qualidade da água em seus habitats. Em tempos recentes são um dos grupos que mais fornece novas moléculas bioativas ou com estruturas incomuns. No entanto, são historicamente considerados um grupo de taxonomia complexa e ainda são comuns discussões acerca da sistemática ao nível de ordens ou mesmo da monofilia do grupo. Este cenário começou a ser alterado de forma marcante na última década, a partir de iniciativas multinacionais voltadas a fornecer uma base taxonômica mais sólida. No Brasil, este processo foi acompanhado pela publicação de guias de identificação para as esponjas do nosso litoral. Partindo dos dados esporádicos disponíveis em períodos anteriores, diversas iniciativas foram feitas especificamente voltadas para o levantamento das espécies de Porifera, principalmente nas regiões costeiras. Tais ações fornecem atualmente aos pesquisadores iniciantes uma base de conhecimento bem mais abrangente do que a disponível na década anterior. Nos dez anos passados desde as últimas listagens feitas para o Estado de São Paulo, houve uma alteração significativa no quadro apresentado. Conforme pôde ser verificado neste trabalho, o período foi sem sombra de dúvida o mais prolífico no que se refere ao conhecimento da espongiofauna local.

The sponges (Porifera) are one of the oldest extant metazoans, but still easily found in a wide variety of aquatic environments. They are key components in several ecosystems, directly influencing the quality of water in their habitat. In recent times, these organisms have become one of the most productive groups in providing new compounds with bioactivity or unusual structures. However, sponges are historically considered a group of complex taxonomy, and systematic discussions at order level or even about the monophyly of the group are still common. This situation began to change markedly in the last decade, with multinational initiatives aimed at providing a more solid taxonomic basis. In Brazil, this process was accompanied by the publication of identification guides of the native species. Starting from the sporadic data available in earlier periods, several initiatives were specifically targeted at the survey of Porifera species, particularly in coastal regions. Such actions now provide the researchers with a knowledge base far more comprehensive than that available a decade earlier. In the ten years since the last checklists for the São Paulo State were published, there was a significant change in the scenario. As verified by this study, the period was undoubtedly the most prolific regarding the knowledge of the local spongiofauna.