Culture of neural cells of the eyestalk of a mangrove crab is optimized on poly-L-ornithine substrate

Allatostatin-C signaling in the crab Carcinus maenas is implicated in the ecdysis program

The allatostatin (AST) family of neuropeptides are widespread in arthropods. The multitude of structures and pleiotropic actions reflect the tremendous morphological, physiological and behavioral diversity of the phylum. Regarding the AST-C (with C-terminal PISCF motif) peptides, crustaceans commonly express three (AST-C, AST-CC and AST-CCC) that have likely arisen by gene duplication. However, we know little regarding their physiologically relevant actions. Here, we functionally characterize the cognate receptor for AST-C and AST-CC, determine tissue expression, and comprehensively examine the localization of AST mRNA and peptide. We also measured peptide release, circulating titers and performed bioassays to investigate possible roles. AST-C and AST-CC activate a single receptor (AST-CRd), but this, and other candidate receptors, were not activated by AST-CCC. Whole-mount in situ hybridization and hybridization chain reaction fluorescent in situ hybridization complemented neuropeptide immunolocalization strategies and revealed extensive expression of AST-Cs in the central nervous system. AST-C or AST-CCC expressing neurons were found in the cerebral ganglia, but AST-CC expression was never observed. Of note, we infer that AST-C and AST-CC are co-expressed in every neuron expressing crustacean cardioactive peptide (CCAP) and bursicon (BURS); all four peptides are released from the pericardial organs during a brief period coinciding with completion of emergence. In contrast to other studies, none of the AST-C peptides exhibited any effect on ecdysteroid synthesis or cardiac activity. However, expression of the AST-C receptor on hemocytes suggests a tantalizing glimpse of possible functions in immune modulation following ecdysis, at a time when crustaceans are vulnerable to pathogens.

Use of invertebrates to model chemically induced parkinsonism-symptoms

The prevalence of neurological diseases is currently growing due to the combination of several factor, including poor lifestyle and environmental imbalance which enhance the contribution of genetic factors. Parkinson's disease (PD), a chronic and progressive neurological condition, is one of the most prevalent neurodegenerative human diseases. Development of models may help to understand its pathophysiology. This review focuses on studies using invertebrate models to investigate certain chemicals that generate parkinsonian-like symptoms models. Additionally, we report some preliminary results of our own research on a crustacean (the crab Ucides cordatus) and a solitary ascidian (Styela plicata), used after induction of parkinsonism with 6-hydroxydopamine and the pesticide rotenone, respectively. We also discuss the advantages, limits, and drawbacks of using invertebrate models to study PD. We suggest prospects and directions for future investigations of PD, based on invertebrate models.

A carboxymethyl lentinan layer by layer self-assembly system as a promising drug chemotherapeutic platform

Surface functionalization of mesoporous silica nanoparticles (MSNs) has been proposed as an efficient strategy for enhancing the biocompatibility and efficiency of an MSN-based carrier platform. Herein, natural polyelectrolyte multilayers composed of poly-l-ornithine (PLO) and carboxymethyl lentinan (LC) were coated on the surface of MSNs through a layer-by-layer (LbL) self-assembly technique, and were characterized by ζ-potential, FTIR, ¹³C NMR, SEM, TEM, XRD, and TG. The prepared carrier presented alternating positive and negative potentials when coated with the polyelectrolytes, and the surface of MSN-PLO/LC was rougher compared to the naked MSNs. The biocompatibility tests, including cytocompatibility, hemocompatibility, and histocompatibility, showed that MSNs biocompatibility could be improved by modifying LC. A high loading and sustained release drug delivery system was constructed after loading doxorubicin (DOX) into the prepared MSN-PLO/LC, which exhibited significant anti-proliferative efficiency in human cervical cancer cell lines (Hela). Therefore, the PLO/LC LbL NPs (layer-by-layer self-assembled nanoparticles coated with PLO/LC layers) based on MSNs, which is easily prepared by electrostatic interactions, can be considered a promising drug chemotherapeutic platform and delivery technique for future human cervical cancer therapy.

Cell proliferation in the central nervous system of an adult semiterrestrial crab

Neurogenesis occurs in adults of most organisms, both vertebrates and invertebrates. In semiterrestrial crabs of the infraorder Brachyura, the deutocerebrum, where neurogenesis occurs, processes the olfactory sensory information from the antennae. The deutocerebrum is composed of a pair of olfactory lobes associated with cell clusters 9 and 10 (Cl 9 and Cl 10), containing proliferating cells. Because the location of the neurogenic niche in brachyuran semiterrestrial crabs has not been defined, here we describe a neurogenic niche in the central olfactory system of the crab Ucides cordatus and report two types of glial cells in the deutocerebrum, based on different markers. Serotonin (5-hydroxytryptamine) labeling was used to reveal neuroanatomical aspects of the central olfactory system and the neurogenic niche. The results showed a zone of proliferating neural cells within Cl 10, which also contains III beta-tubulin (Tuj1)+ immature neurons, associated with a structure that has characteristics of the neurogenic niche. For the first time, using two glial markers, glial fibrillary acidic protein (GFAP) and glutamine synthetase (GS), we identified two types of astrocyte-like cells in different regions of the deutocerebrum. This study adds to the understanding of neurogenesis in a brachyuran semiterrestrial crustacean and encourages comparative studies between crustaceans and vertebrates, including mammals, based on shared aspects of both mechanisms of neurogenesis and regenerative potentials.

Primary biocompatibility tests of poly(lactide-co-glycolide)-(poly-L-orithine/fucoidan) core-shell nanocarriers

Layer-by-layer (LbL) self-assembly is the technology used in intermolecular static electricity, hydrogen bonds, covalent bonds and other polymer interactions during film assembling. This technology has been widely studied in the drug carrier field. Given their use in drug delivery systems, the biocompatibility of these potential compounds should be addressed. In this work, the primary biocompatibility of poly(lactide-co-glycolide)-(poly-L-orithine/fucoidan) [PLGA-(PLO/fucoidan)] core-shell nanoparticles (NPs) was investigated. Atomic force microscopy revealed the PLGA-(PLO/Fucoidan)₄ NPs to be spherical, with a uniform size distribution and a smooth surface, and the NPs were stable in physiological saline. The residual amount of methylene chloride was further determined by headspace gas chromatography, in which the organic solvent can be volatilized during preparation. Furthermore, cell viability, acridine orange/ethidium bromide staining, haemolysis and mouse systemic toxicity were all assessed to show that PLGA-(PLO/fucoidan)₄ NPs were biocompatible with cells and mice. Therefore, these NPs are expected to have potential applications in future drug delivery systems.

Synthesis and characterization of innovative poly(lactide-co-glycolide)-(poly-l-ornithine/fucoidan) core–shell nanocarriers by layer-by-layer self-assembly

Layer-by-Layer (LbL) self-assembly of nanocarriers has garnered the interest of researchers for a wide variety of biomedical applications.