Human Placenta - A Perfect Matrix to Connect the Biomarkers of Environmental Exposure to Biomarkers of Effect

摘要

The exposome of real organisms is defined as the measure of all the exposures of an individual in a lifetime and how those exposures relate to disease. Some exposure starts already in early life at prenatal conditions and leads to the onset of diseases in later life. To study prenatal exposure, the placenta is becoming a key tissue. In fact, due to its size, it is possible to analyze both the exogenous and the endogenous chemical substances. In addition, it is known, that placenta play a key role in the metabolism and detoxification of several drugs, compounds in diet, as well as environmental contaminants. Therefore, human placenta can also be used to identify possible biomarkers of environmental exposure and to link them to biomarkers of possible adverse outcomes. In several recent papers, to find the potential bridge between external exposure and biological response, researchers have reported the "meet-in-metabolite" method of analysis. Large part of these studies were conducted using human fluids such as urine or blood but we have supposed that placenta, for its characteristics, could also be a good matrix for this approach. For this purpose, we have analyzed in the human placenta some important biomarkers such as thyroid hormones and catecholamines. We have investigated the distribution of some metals, as well as the distribution of some persistent organic pollutants (e.g., polychlorinated dibenzo-p-dioxins and dibenzofurans, polychlorinated biphenyls, and polybrominated diphenyl ethers). Finally, we have studied if those molecules were homogenously distributed in the tissue. The results suggested that placenta could be a good matrix to correlate biomarkers of exposure to biomarkers of effects, although the sampling mode should be taken into consideration to avoid misleading results.