Metallothioneins (MTs) are proteins responsible for metal detoxification, radical scavenging, and play
a role in immunity and infection. MTs occur throughout the animal kingdom in earthworms three
isoforms have been identified, one of which is specifically detoxifying Cadmium (Cd). Cd is introduced
into the environment through agriculture and industry and can cause, depending on exposure
concentration and duration, various kinds of cellular damage. Cd-induced induction of MTs is therefore
important to survive in contaminated environments.
We observed that MT gene expression during Cd stress was suppressed when earthworms were
wounded and therefore suggested that the stress response and immune reaction are linked on the
molecular level.
The present project aims at understanding how and why MTs are downregulated during wound
healing. We hypothesize that limitations of essential trace elements and/or energy reserves could lead
to a decrease in MT gene activity. We will furthermore investigate transcriptional regulators to reveal
the molecular coordination of these cellular processes. Revealing if the earthworms immune cells
underlie a so-called metabolic switch that drives the function towards either detoxification or
immunity will further our understanding of the cellular part of the innate immune response.
Taken together, we will gain detailed information how earthworms cope with stress like Cadmium
exposure and injury with a focus on stress-induced MT regulation.