Effects of cadmium on mitochondrial structure and function in different organs: studies on the soil centipede Lithobius forficatus (Myriapoda, Chilopoda)

Abstract

Mitochondria are organelles that play a crucial role in cell physiology, cell death, and aging. They are among the first responders to different stressors that originate from the environment. Cadmium as a heavy metal affects different levels of body organization: from organs through tissues and cells to organelles. Based on our previous research results, we decided to check how the exposure to cadmium affects the functioning of mitochondria in different organs of soil living centipede Lithobius forficatus. The activity of mitochondria in somatic and germ cells has been analyzed using transmission electron microscopy (TEM), confocal microscopy, and flow cytometry. Changes in the mitochondrial membrane potential and mitochondrial dismutase (MnSOD) activity in relation to the accumulation of reactive oxygen species (ROS) caused by cadmium exposure have been studied. Individuals were divided into 3 experimental groups depending on cadmium concentration in soil. Changes in mitochondrial ultrastructure caused by cadmium are tissue-dependent and associated with an increase of ROS levels. The system of ROS and MnSOD activation works more efficiently in the case of gonads than in the digestive system. While the short-term cadmium exposure alters the fine structure of both the somatic and germ-line cells in gonads, the long-term cadmium exposure causes mitochondrial ultrastructure regeneration.