Oliverio, M. | bioRxiv Science

bioRxiv2024

The proteotranscriptomic characterization of venom in the white seafan Eunicella singularis elucidates the evolution of Octocorallia arsenal

All the members of the phylum Cnidaria are characterized by the production of venom in specialized structures, the nematocysts. Venom of jellyfish (Medusozoa) and sea anemones (Anthozoa) has been investigated since the 1970s, revealing a remarkable molecular diversity. Specifically, sea anemones harbour a rich repertoire of neurotoxic peptides, some of which have been developed in drug leads. However, venoms of the vast majority of Anthozoa species remain uncharacterized, particularly in the class Octocorallia. To fill this gap, we applied a proteo-transcriptomic approach to investigate the venom composition in Eunicella singularis, a gorgonian species common in Mediterranean hard-bottom benthic communities. Our results highlighted the peculiarities of the venom of E. singularis with respect to sea anemones, which is reflected in the presence of several toxins with novel folds, worthy of functional characterization. A comparative genomic survey across the octocoral radiation allowed us to generalize these findings and provided insights into the evolutionary history, molecular diversification patterns and putative adaptive roles of venom toxins. A comparison of whole-body and nematocyst proteomes revealed the presence of different cytolytic toxins inside and outside the nematocysts. Two instances of differential maturation patterns of toxin precursors were also identified, highlighting the intricate regulatory pathways underlying toxin expression.

evolutionary biology↗

bioRxiv2019

Senescence-associated metabolomic phenotype in primary and iPSC-derived mesenchymal stromal cells

Long-term culture of primary cells is reflected by functional and secretory changes, which ultimately result in replicative senescence. In contrast, induced pluripotent stem cells (iPSCs) do not reveal any signs of cellular aging while in the pluripotency state, whereas little is known how they senesce upon differentiation. Furthermore, it is largely unclear how the metabolome of cells changes during replicative senescence and if such changes are consistent across different cell types. In this study, we have directly compared culture expansion of primary mesenchymal stromal cells (MSCs) and iPSC-derived MSCs (iMSCs) until they reached growth arrest after a mean of 21 and 17 cumulative population doublings, respectively. Both cell types acquired similar changes in morphology, in vitro differentiation potential, up-regulation of senescence-associated beta-galactosidase, and senescence-associated DNA methylation changes. Furthermore, MSCs and iMSCs revealed overlapping gene expression changes during culture expansion, particularly in functional categories related to metabolic processes. We subsequently compared the metabolome of MSCs and iMSCs at early and senescent passages and observed various significant and overlapping senescence-associated changes in both cell types, including down-regulation of nicotinamide ribonucleotide and up-regulation of orotic acid. Replicative senescence of both cell types was consistently reflected by the metabolic switch from oxidative to glycolytic pathways. Taken together, long-term culture of iPSC-derived MSCs evokes very similar molecular and functional changes as observed in primary MSCs. Replicative senescence is associated with a highly reproducible senescence-associated metabolomics phenotype, which may be used to monitor the state of cellular aging.

cell biology↗