Molecular effects of copper on the reproductive system of mytilus galloprovincialis

Abstract

This study aims to assess the effects induced by 24 hr exposure to a subtoxic copper concentration on the reproductive system (gonads, spermatozoa, and protamine-like[PL] proteins) of Mytilus galloprovincialis. Inductively coupled plasma-mass spectrometry indicated accumulation of this metal in gonads, spermatozoa, and PL proteins of exposed mussels. Further, real-time polymerase chain reaction analyses showed altered expression levels of mt10 and PL proteins genes in spermatozoa and gonads, respectively, of exposed mussels. Protamine-like proteins, which represent the main basic component of sperm chromatin of this organism, showed a higher DNA binding affinity and a different DNA binding mode in exposed mussels. Moreover, an increased amount of NaCl was required for the release from sperm nuclei of PL-III, the main PL protein component. Finally, PL proteins extracted from exposed mussels promoted DNA oxidative damage in the presence of H 2 O 2. These results demonstrate that the tolerable copper amount could also affect the properties of PL proteins and determine the negative effects on the reproductive system of this organism. These analyses could be useful to develop quick and efficient chromatin-based genotoxicity tests for pollution biomonitoring programs.

Discovery of the Involvement in DNA Oxidative Damage of Human Sperm Nuclear Basic Proteins of Healthy Young Men Living in Polluted Areas

“…Therefore, it is of fundamental importance to conduct in vivo studies on DNA oxidative damage, since the results that can be obtained are an order of magnitude more complex than those obtained by treating only DNA in vitro. These observations are in agreement with our in vivo studies on SNBP from mussels exposed to subtoxic concentrations of heavy metals, such as copper or cadmium [ 5 , 29 ]. In fact, we found that the heavy metals measured in gonads accumulated mainly in the fraction of SNBP, causing their involvement in DNA oxidative damage [ 5 , 30 ].…”

“…DNA is the vital carrier of genetic information in all living cells, but its chemical stability is affected by several factors. In fact, DNA is highly susceptible to chemical modifications by exogenous agents such as ionizing radiation and ultraviolet light [ 1 , 2 , 3 ] and by several environmental contaminants (pesticides, hydrocarbons, and especially heavy metals), which can generate oxidative stress [ 4 , 5 ]. Beyond environmental agents, DNA is also subject to oxidative damage from by-products of cellular metabolism (endogenous agents).…”

Molecular effects on spermatozoa of Mytilus galloprovincialisexposed to hyposaline conditions

“…This DNA binding mode was found both for the PL proteins deriving from mussels exposed to 17.1 and 35.9 psu conditions and for those deriving from mussels exposed to 22.6 and 26.2 psu. This suggested that hyposalinity exposure did not affect DNA binding mode of PL proteins, different from what we have seen while exposing mussels to copper chloride (Lettieri et al, ). In that case, we observed an increase in DNA binding affinity and also a change of DNA binding mode from “all or nothing” to “intermediate mode”, the typical DNA binding mode of somatic H1 histone (Piscopo et al, ).…”

Novel Insights into Mercury Effects on Hemoglobin and Membrane Proteins in Human Erythrocytes

“…The toxic biological effects of human exposure to these metals are extremely numerous. Among the molecular mechanisms underlying their toxicity, protein interactions seem to play a key role, possibly leading to structural and functional alterations, thus interfering with important metabolic as well as regulatory cellular function [ 33 , 42 , 43 , 44 ].…”