Induction of apoptosis in mussel Mytilus galloprovincialis gills by model cytotoxic agents

Abstract

Apoptosis signaling pathway was investigated in the marine mussel Mytilus galloprovincialis exposed to various stressors. Analyses were performed in mussels exposed to two major pollutants of the aquatic environment: tributyltin and the water soluble fraction of diesel oil, for 1 h and animals were then maintained in sea water for a recovery period of 6 and 24 h. Apoptosis was evaluated at several levels of the cell signaling cascade by measuring Bcl-xS expression, caspase-3 activity and DNA damage (Fast micromethod(®) and TUNEL techniques). H(2)O(2) was used as a control of apoptosis induction for validation of the assays. Results showed an induction of Bcl-xS expression, a protein implicated in apoptosis, after 1 h exposure to all concentrations of chemicals. Moreover, in the same manner, apoptotic DNA damage was induced with all chemicals tested. Besides, caspase 3 activity was detected after 1 h exposure to low doses of TBT and diesel oil while the high concentrations induced this protein after 6 h. The achieved data were also correlated with our previous study, demonstrating an induction of the mitogen-activated protein kinase (MAPK) activity in the mussel M. galloprovincialis exposed to the same conditions. In conclusion, this study was one of the first characterizing the MAP kinase cell signaling pathway leading to apoptosis in the mussel M. galloprovincialis exposed to chemicals. It showed for the first time that the Bcl-xS protein was present in these mussels as in other species and played a role in apoptosis mediation. Moreover, the main originality of this work was that it showed that two apoptotic pathways might be present in the mussel: a caspase 3-dependent and a caspase 3-independent pathways.

Protective effect of rhein against oxidative stress-related endothelial cell injury

“…In the present study, high concentrations of H 2 O 2 led HUVECs to undergo apoptosis, which is consistent with the findings of other studies (23,24). However, the mechanisms of apoptosis are quite complex and are controlled by various pathways and signals (25). The underlying mechanisms of H 2 O 2 -induced HUVEC apoptosis involved apoptosis-related regulation signals, such as Bcl-2 and the caspase families (23).…”

Genes of the Mitochondrial Apoptotic Pathway in Mytilus galloprovincialis

“…Bcl-2 family proteins control MOMP in vertebrates [23]. Various members of this family, such as Bag, Bcl-xL and Bcl-xS, have recently been described in oysters and mussels [59], [60].…”

The complexity of apoptotic cell death in mollusks: An update

“…Several sequences of mitochondrial factors released during the MOMP, such as SMAC/Diablo, and several AIF proteins have been described in oysters and mussels (C. gigas, M. galloprovincialis and M. edulis) [11,97,119,147]. Moreover, several ESTs of an APAF-1 interacting protein (APIP) have been identified in the clams R. decussatus and R. philippinarum [82] (Fig.…”

“…However, activation of cytosolic BH3-only proteins promotes Bax/Bak protein conformational change and protein oligomerization, which induces large pore formation in the outer mitochondrial membrane [26,89]. Different members of the Bcl-2 family (Bcl-xL, Bcl-xS, Bag, Bcl2 and Bax) have been described in the bivalve mollusks C. gigas and M. galloprovincialis [11,28,147,148] (Fig. 1).…”