AGNELLO, Maria

AMATO G

FILOSTO, Simone

ROCCHERI, Maria Carmela

SPRIO C

Archivio istituzionale della ricerca - Università di Palermo

III Congresso Annuale Dipartimento di Biologia Cellulare e dello Sviluppo, Università di Palermo    21-22 Dicembre 2005  RESPONSE TO CADMIUM STRESS IN SEA URCHIN EMBRYOS Maria Agnello, S. Filosto, C. Sprio, G. Amato, M. C. Roccheri Dipartimento di Biologia Cellulare e dello Sviluppo “A. Monroy”, Università degli Studi di Palermo.  Cadmium is a heavy metal considered one of the most toxic pollutants both in terrestrial ecosystems and in aquatic environments. Since it is a permanent metal ion, which cannot be degraded by bacteria, it is accumulated by many organisms causing a series of toxic effects such as: enhanced production of reactive oxygen species (Stohs et al, 2001), depletion of glutathione (Shimizu et al, 1997), inhibition of enzymes involved in DNA synthesis and repair (Yang et al, 1996) and DNA single-strand breaks (Schroder et al, 1999). Marine organisms are highly sensitive to many environmental cues and, consequently, the analysis of their bio-molecular responses to different stress agents is very important for the understanding of putative repair mechanisms. Paracentrotus lividus is a very suitable and significant model system for testing how specific stresses can simultaneously affect development and protein synthesis. In fact, it was demonstrated that sea urchin embryos use a typical protective strategy against many kinds of stresses. (Roccheri et al., 1993 and 1988; Casano et al., 1998; Giudice et al., 1999; Gianguzza et. al., 2000; Roccheri et al., 2000 and 2001). Using AAS experiments we have assayed the bioaccumulation of cadmium in sea urchin embryos treated since fertilization with CdCl2 1 mM. An intracellular accumulation followed by a saturation model has been shown for this metal (Fig. 1). We found that between 15 and 24 hours of exposure to sub lethal cadmium concentration the synthesis of a specific set of stress proteins (hsps 90kDa, 70- 72kDa, 56kDa, 28kDa, 25kDa) was induced and that the rate of synthesis of a certain sub-set (70- 72kDa, 56kDa, 25kDa) increased as the exposure time incremented. Recovery experiments in which cadmium was removed showed that while stress proteins continued to be synthesized, the development of the embryos was resumed only after short-time exposures. (Roccheri et al.; 2004). It is true that many organisms can develop mechanisms of cellular programmed death (apoptosis) in response to an excessive accumulation of a toxic metal like cadmium (Samali & Cotter, 1996; Hamada et al., 1997). TUNEL assays on whole mount embryos showed that a long exposure triggers severe fragmentation of DNA. Immunocytochemical experiments with embryos treated with cadmium and reacted with both anti-cleaved-caspase-3 and anti-pro-caspase-3 antibodies, showed an increase of cleaved caspase-3 and a decrease of pro-caspase-3, depending on the length of treatment. Likewise the expression of cleaved forms of α-Fodrin (an anchorage cytoskeleton protein) and of Lamin A (nuclear membrane protein), substrates of caspase-3 and caspase-6 respectively, appeared to increase during treatment with cadmium. In addition, PARP cleaved form, the expression of which depends on the proteolytic activity of caspase-3 and/or caspase-7, exhibited a similar increasing expression. Therefore we assayed the role of caspase-7-cleaved in the apoptotic pathway. Our results have shown that caspase-7 is involved in this mechanism. Cadmium-induced apoptosis has been well documented, but the possible implication and regulation of both intrinsic and extrinsic pathways are uncertain. The mechanism through which apoptosis begins and performs needs futher investigation.  Key words: APOPTOSIS, CADMIUM, SEA URCHIN EMBRYOS.  References: - Casano C, Roccheri MC, Onorato K, Cascino D, Gianguzza F. 1998. “Deciliation: A stressful event for Paracentrotus lividus embryos”. Biochem Biophys Res Commun 248: 628-34. - Gianguzza F, Ragusa MA, Roccheri MC, Di Liegro I, Rinaldi AM. 2000. “Isolation and characterization of a Paracentrotus lividus cDNA encoding a stress-inducible chaperonin”. Cell Stress Chaperones 5:87-89. - Giudice G, Sconzo G, Roccheri MC. 1999. “Studies on heat shock proteins in sea urchin development”. Develop Growth Diff 41: 375-80. - Hamada T, Tanimoto A, Sasaguri Y 1997. “Apoptosis induced by cadmium”. Apoptosis 2, 359-367. - Roccheri MC, Agnello M, Bonaventura R, Matranga V 2004. “Cadmium induces the expression of specific stress proteins in sea urchin embryos”. Biochem Biophys Res Commun. 321, 80-87. - Roccheri MC, Cascino D, Giudice G. 1993. “Two-dimensional electrophoretic analysis of stress proteins in Paracentrotus lividus”. J Submicr Cytol Pathol 25: 173-9. - Roccheri MC, La Rosa M, Ferraro MG, Cantone M, Cascino D, Giudice G, Sconzo G 1988. “Stress proteins by zinc ions in sea urchin embryos”. Cell Diff 24: 209-14. - Roccheri MC, Onorato K, Tipa C, Casano C. 2000. “EGTA treatment causes the synthesis of Hsps in sea urchin embryos”.  Mol Cell Biol Res Commun 3: 306-11. - Roccheri MC, Patti M, Agnello M, Gianguzza F, Carra E, Rinaldi AM. 2001. “Localization of mitochondrial Hsp56 chaperonin during sea urchin development”. Biochem Biophys Res Commun 287: 1093-98. - Samali A § Cotter TG. 1996. “Heat shock proteins increase resistance to apoptosis”. Exp Cell Res 223: 167-70. - Schroder H.C., Hassanein H.M.A., Lauenroth S., Koziol C., Mohamed T.AA., Lacorn M., Steinhart H., Batel R., Muller WEG. 1999. “Induction of DNA strand breaks and expression of HSP70 and GRP78 homolog by cadmium in the marine sponge suberites domuncula”. Arch Environ Contam Toxicol 36: 47-55. - Shimizu M., Hochadel J.F., Waalkes M.P. 1997. “Effects of glutathione depletion on cadmium-induced metallothionein synthesis, cytotoxicity, and proto-oncogene expression in cutured rat myoblasts”. J. Toxicol. Environ. Health 51, 609-21. - Stohs S.J., Bagchi D., Hassoun E., Bagchi M. 2001. “Oxidative machenism in the toxicity of chromium and cadmium ions”. J Environ Pathol Toxicol and Oncol. 20: 77-88. - Yang SW, Becker FF, and Chan JY. 1996 Inhibition of human DNA ligase I activity by zinc and cadmium and the fidelity of ligation. Environ Mol mutagen 28: 19-25 05101520253035Treatment       Control    15h      21h      24h Fig. 1: Q.ty (µg) in 100mg of embryos   

Response to cadmium stress in sea urchin embryos

https://iris.unipa.it/retrieve/handle/10447/14865/15173/dbcs%202005%20agnello.pdf

Response to cadmium stress in sea urchin embryos

Abstract

Similar works

Full text

Available Versions

Archivio istituzionale della ricerca - Università di Palermo