Radial nerve cord protein phosphorylation dynamics during starfish arm tip wound healing events

Abstract

Echinoderms, as invertebrate deuterostomes, have amazing neuronal intrinsic growth aptitude triggered at any time point during the animal lifespan leading to successful functional tissue regrowth. This trait is known to be in opposition to their mammal close phylogenic relatives that have lost the ability to regenerate their central nervous system. Despite the promising nature of this intrinsic echinoderm trait, it was only recently that this complex biological event started to be unveiled. In the present study, a 2DE gel-based phosphoproteomics approach was used to investigate changes in starfish neuronal protein phosphorylation states at two different wound healing time-graded events following arm tip amputation, 48 h and 13 days. Among the resolved protein spots in 3.0-5.6 NL pH IEF strips, 190, 142, and 124 had a phosphoprotein signal in the control and the two injury experimental groups, respectively. Gel image analysis, highlighted 129 spots with an injury-related protein phosphorylation dynamics, several being exclusively phosphorylated in controls (72 spots), injured nerves (8 spots) or, showing significantly different phosphorylation ratios (37 spots). Within these, a total of 43 proteins were identified with MALDI-TOF/TOF. Altogether, several intervening proteins of important injury-signaling pathways that seem to be modulated through phosphorylation, were identified for the first time in starfish radial nerve cord early regeneration events. These include cytoskeleton re-organization toward the formation of the neuronal growth cones; cell membrane rearrangements, actin filaments, and microtubules dynamics; mRNA binding and transport; lipid signaling; Notch pathway; and neuropeptide processing.

Top‐down proteomics: Enhancing 2D gel electrophoresis from tissue processing to high‐sensitivity protein detection

“…Thus, AFD is an important tool in addressing sample handling/preparation issues, particularly those that restrict full protein extraction. We have utilised AFD in the analysis of a number of different tissues, as have others, and improvements in proteome analyses are consistently seen . This approach also enables truly quantitative , parallel analyses of proteomes and transcriptomes .…”

Neurons and Glia Cells in Marine Invertebrates: An Update

“…It is remarkable the possibility to carry out this kind of studies in all class of the Phylum Echinodermata. There are evidence of NS regeneration in Asteroidea species as Marthasterias glacialis (Franco et al, 2012), Asterias rubens (Moss et al, 1998), and Ophiocoma echinata (Pomory and Lawrence, 1999); in Ophiuroidea like Ophioderma longicaudum and Amphiura filiformis (Dupont and Thorndyke, 2006;Biressi et al, 2010); in Eupentacta fraudatrix (Mashanov et al, 2008), and Cladolabes schmeltzii (Kamenev and Dolmatov, 2015) class Holothuroidea; in the Echinoidea Psammechinus miliaris (Chia, 1970); and in the Crinoidea Antedon mediterranea (Candia Carnevali et al, 1997). In all cases, evidence indicates that during the lifespan of these organisms an unusual NS regeneration program can be activated by distinct neurotrophic factors that include morphogens, mitogens, and growth and/or regulatory molecules.…”

Understanding regeneration through proteomics

“…In proteomics the current information is restricted to the proteome characterization of a few echinoderm species and tissues. Specifically on regeneration, the information is even more sparse, and to the best of our knowledge, our group was the first to apply a differential proteomic approach to pinpoint protein pathways relevant during starfish radial nerve cord regeneration events . In the majority of the proteomic characterization of echinoderm tissues, 2‐DE was the technique of choice .…”

“…Recently, proteomic tools were also used to understand the regeneration events of echinoderms radial nerve cord. In this study, Franco et al used a differential proteomic approach to track the changes in starfish neuronal protein phosphorylation states at two different wound healing time‐graded events after Marthasterias glacialis arm‐tip ablation . Within this study, a total of 43 proteins were successfully identified belonging to important injury signaling pathways that were modulated through phosphorylation during starfish radial nerve cord early regeneration events.…”