A hungry need for knowledge on the black soldier fly digestive system

The interest towards the black soldier fly (BSF), Hermetia illucens, has grown impressively in the last few years, fostered by the legislative changes in the European landscape that have lifted the ban regarding the use of BSF larvae as feedstuff. In addition, bioconversion mediated by the larvae of the BSF is viewed as one of the most promising technologies for organic waste processing and valorisation. Finally, new, alternative applications to exploit various larval products such as lipids, chitin, antimicrobial peptides, and frass are being explored. However, this positive trend, confirmed by the increasing number of companies that deal with BSF mass rearing and processing, is in sharp contrast with the limited information on the biology of this insect, in particular on aspects related to its digestive features. This lack of knowledge needs to be carefully considered and filled in coming years, as a deep characterisation of the morphology, physiology, transcriptomics, and proteomics of the digestive system of the insect, as well a fine dissection of related aspects as gut microbiota and pathogens, is a prerequisite to improve the amazing bioconversion capabilities of this dipteron. So far, the larval stages received the most attention in research, but there might still be a lot to win by focusing more on the adult stage. Further expanding the basic knowledge on both the larval and the adult gut could lead to unexpected findings and open new perspectives to produce value-added bioproducts

In Vivo Isolation and Characterization of Stem Cells with Diverse Phenotypes Using Growth Factor Impregnated Biomatrices

BACKGROUND: The stimulation to differentiate into specific cell types for somatic stem cells is largely due to a series of internal and external signals coming from the microenvironment that surrounds the stem cell. Even though intensive research has been made, the basic mechanisms of plasticity and/or the molecules regulating stem cells proliferation and differentiation are not completely determined. Potential answers concerning the problems could be derived from the studies of stem cells in culture. METHODOLOGY/PRINCIPLE FINDINGS: We combine a new procedure (using the matrigel biopolymer supplemented with a selected cytokine/growth factor) with classic techniques such as light, confocal and electron microscopy, immunohistochemistry and cell culture, to perform an analysis on stem cells involved in the leech (Hirudo medicinalis) repair tissues. The leech has a relative anatomical simplicity and is a reliable model for studying a variety of basic events, such as tissue repair, which has a striking similarity with vertebrate responses. Our data demonstrate that the injection of an appropriate combination of the matrigel biopolymer supplemented with a selected cytokine/growth factor in the leech Hirudo medicinalis is a remarkably effective tool for isolating a specific cell population in vivo. A comparative analysis of biopolymer in vivo sorted stem cells indicates that VEGF recruited cells of a hematopoietic/endothelial phenotype whereas MCP-1/CCL2 isolated cells that were of an early myeloid lineage. CONCLUSION: Our paper describes, for the first time, a method allowing not only the isolation of a specific cell population in relation to the cytokine utilized but also the possibility to culture a precise cell type whose isolation is otherwise quite difficult. This approach could be broadly applied to isolate stem cells of diverse origins based on the recruitment stimuli employed

Ras activation in Hirudo medicinalis angiogenic process

In some leeches like Hirudo medicinalis, any kind of stimulation (surgical wound or growth factor injection) provokes the botryoidal tissue response. This peculiar tissue, localized in the loose connective tissue between gut and body wall, is formed by granular botryoidal cells and flattened endothelial-like cells. Under stimulation, the botryoidal tissue changes its shape to form new capillaries. In mammals, the molecular regulation of the angiogenic phenotype requires coordinated input from a number of signalling molecules: among them the GTPase Ras is one of the major actor. In our current study, we determine whether Ras activation alone would be sufficient to drive vessels formation from leech botryoidal tissue. Our findings indicate that assembly and disassembly of actin filaments regulated by Ras protein is involved in morphological modification of botryoidal tissue cells during leech angiogenic process

Hirudo medicinalis as alternative model for in vivo and in vitro studies on nanomaterials toxicity.

Due to the steady increase of production and use of engineered nanomaterials (NMs), intentional or unintentional discharges into the environment may occur. Since it is critical to develop new methods to fully understand NMs bioaccumulation and cytotoxicity, a reliable model in which analyze NMs effects both in vivo and in vitro is more than ever necessary. Here we propose the leech, Hirudo medicinalis, as alternative animal model to study multi-walled carbon nanotubes (MWCNTs) effects by means of an extended study that includes in vivo and in vitro treatments. First, MWCNTs were dispersed in leeches\u2019 water to mimic a possible environmental exposure. In a second assay, a MWCNTs-supplemented biomatrix was injected in leeches\u2019 body wall. Thirdly, leeches macrophages were isolated and cultured to analyze their responses after MWCNTs in vitro treatment. Our results show that water dispersed MWCNTs evoke in the leech body wall a strong inflammatory response, involving mainly monocyte-macrophages cells. Ultrastructural analysis of MWCNTs-supplemented biomatrix revealed that in leech macrophages MWCNTs are internalized both in an active (phagocytosis) and a passive manner (membrane piercing). Finally, MWCNTs in vitro treatment cause the decrease of cell proliferation rate and the increase of ROS production and of the apoptotic rate. Our combined experimental approaches, not only attest the ability of MWCNTs in inducing a potent inflammatory response, but also confirm Hirudo medicinalis as a good alternative model that can be successfully used to study, both in vivo and in vitro, the possible harmful effects of any nanomaterial

Further studies on the gangliosidic nature of the cholinergic-specific antigen, Chol-1.

The antigen designated as Chol-1 beta, detected by an antiserum specific for cholinergic neurons, has been purified to homogeneity from ganglioside mixtures extracted from Torpedo electric organ and pig brain. The final products from the two sources behaved identically in a wide range of tests and gave coincident immunopositive and Ehrlich-positive spots after thin layer chromatography in seven different solvent systems; they were thus considered to be identical and to constitute a single, pure chemical species. Gas-chromatographic analysis revealed the presence of long-chain bases, glucose, galactose, N-acetylgalactosamine, and sialic acid in integral molar ratios of 1:1:2:1:3; the compound's reactivity to cholera toxin after Vibrio cholerae sialidase treatment on thin layer chromatography and the recovery of GM1 as sole product of exhaustive sialidase treatment identified it as a member of the gangliotetrahexosyl series. From the products of partial enzymatic desialylation and treatment with beta-galactosidase and a comparison of the compound's immunoreactivity to anti-Chol-1 antisera with that of other trisialogangliosides of defined molecular structure, we were able to assign a disialosyl residue alpha-Neu5Ac-(2----8)-alpha-Neu5Ac-(2----3)- to the inner galactose, and we suggest GalNAc as a possible site of linkage of the third sialic acid

Transcriptional and Post-Transcriptional Regulation of Autophagy

Autophagy is a widely conserved process in eukaryotes that is involved in a series of physiological and pathological events, including development, immunity, neurodegenerative disease, and tumorigenesis. It is regulated by nutrient deprivation, energy stress, and other unfavorable conditions through multiple pathways. In general, autophagy is synergistically governed at the RNA and protein levels. The upstream transcription factors trigger or inhibit the expression of autophagyor lysosome-related genes to facilitate or reduce autophagy. Moreover, a significant number of noncoding RNAs (microRNA, circRNA, and lncRNA) are reported to participate in autophagy regulation. Finally, post-transcriptional modifications, such as RNA methylation, play a key role in controlling autophagy occurrence. In this review, we summarize the progress on autophagy research regarding transcriptional regulation, which will provide the foundations and directions for future studies on this self-eating process

A hedgehog-like signal is involved in slow muscle differentation in Sepia officinalis (Mollusca)

In the tentacle of Sepia officinalis, smooth-like, helical and cross-striated fibres deriving from different populations of myoblasts are present. Myoblasts appear at different times during the development and express two muscle-specific transcription factors: Myf5-like and MyoD-like factors. Myoblasts expressing Myf5 give rise to slow fibres, whereas fast fibres derive from MyoD+ myoblasts. We found that a Hedgehog (Hh)-like signal was present in the central nerve cord of the tentacle from the early stages of development and in a specific population of myoblasts which are the precursors of slow muscle fibres. The model showed interesting similarities with vertebrates, in which Sonic hedgehog is a protein secreted by axial structures (the notochord and neurotube) and is involved in slow muscle differentiation and in survival of muscle precursors