Apoptosis: focus on sea urchin development

Abstract

It has been proposed that the apoptosis is an essential requirement for the evolution of all animals, in fact the apoptotic program is highly conserved from nematodes to mammals. Throughout development, apoptosis is employed by multicellular organisms to eliminate damaged or unnecessary cells. Here, we will discuss both developmental programmed cell death (PCD) under normal conditions and stress induced apoptosis, in sea urchin embryos. Sea urchin represent an excellent model system for studying embryogenesis and cellular processes involved in metamorphosis. PCD plays an essential role in sculpting and remodelling the embryos and larvae undergoing metamorphosis. Moreover, this marine organism directly interacts with its environment, and is susceptible to effects of several aquatic contaminants. Apoptosis can be adopted as a defence mechanism against any environmental chemical, physical and mechanical stress, for removing irreversibly damaged cells. This review, while not comprehensive in its reporting, aims to provide an overview of current knowledge on mechanisms to regulate physiological and the induced apoptotic program in sea urchin embryos.

Autophagy as a defense strategy against stress: focus on Paracentrotus lividus sea urchin embryos exposed to cadmium

“…In this context, autophagy might serve as a survival mechanism when cellular damage is not too extensive or may lead to cell death when the damage/stress is persistent and/or irreversible; in the latter case, it can act as an independent pathway or in association with apoptosis (Agnello and Roccheri 2010).…”

Manganese: A New Emerging Contaminant in the Environment

“…In addition, it has been demonstrated that a long-lasting exposure (over 24 hours) triggers DNA fragmentation and causes the activation of caspase-3, one of the key molecules promoting apoptosis, which increased in a time-dependent way (Agnello et al 2006(Agnello et al , 2007. In sea urchin embryos, apoptosis is an important part of the defence strategy, both in physiological or stress conditions (Agnello & Roccheri, 2010).…”

Sea urchin embryos as a model system for studying autophagy induced by cadmium stress

“…11 It was previously demonstrated that subacute/sublethal concentrations of Cd induce, during development of sea urchin embryos, morphological abnormalities, activation of specific stress proteins (heat shock proteins, HSPs), and expression of metallothioneins and apoptosis, in a dose/time-dependent manner. [12][13][14][15][16][17][18] Essentially, Cd exerts its toxic action in the long-term, as it accumulates in cells. It has been suggested that survival systems adopted during embryonic development of sea urchins can operate in tandem through a putative crosstalk.…”

“…It has been suggested that survival systems adopted during embryonic development of sea urchins can operate in tandem through a putative crosstalk. 17 The metallothioneins and HSPs are able to produce a detoxifying and antioxidant effect that is not always sufficient to block the action of the toxic metal, depending on the extent of cell damage. 19,20 In such circumstances the mechanisms of programmed cell death, such as apoptosis, may be triggered.…”