Interactive toxicity of copper and cadmium in regenerating and adult planarians.

In a polluted environment, metals are present as complex mixtures. As a result, organisms are exposed to different metals at the same time, which affects both metal-specific as well as overall toxicity. Detailed information about the molecular mechanisms underlying the adverse effects of combined exposures remains limited in terms of different life stages.

Regenerative responses following DNA damage - β-catenin mediates head regrowth in the planarian .

Pluripotent stem cells hold great potential for regenerative medicine. Increased replication and division, such is the case during regeneration, concomitantly increases the risk of adverse outcomes through the acquisition of mutations. Seeking for driving mechanisms of such outcomes, we challenged a pluripotent stem cell system during the tightly controlled regeneration process in the planarian Exposure to the genotoxic compound methyl methanesulfonate (MMS) revealed that despite a similar DNA-damaging effect along the anteroposterior axis of intact animals, responses differed between anterior and posterior fragments after amputation.

Toxicity Assessment of Silver Nanoparticles in Homeostatic versus Regenerating Planarians.

Silver nanoparticles (AgNPs) belong to the most commercialized nanomaterials, used in both consumer products and medical applications. Despite its omnipresence, in-depth knowledge on the potential toxicity of nanosilver is still lacking, especially for developing organisms. Research on vertebrates is limited due to ethical concerns, and planarians are an ideal invertebrate model to study the effects of AgNPs on stem cells and developing tissues , as regeneration mimics development by triggering massive stem cell proliferation.

Planarians Customize Their Stem Cell Responses Following Genotoxic Stress as a Function of Exposure Time and Regenerative State.

Aiming to in vivo characterize the responses of pluripotent stem cells and regenerative tissues to carcinogenic stress, we employed the highly regenerative organism Schmidtea mediterranea. Its broad regenerative capacities are attributable to a large pool of pluripotent stem cells, which are considered key players in the lower vulnerability toward chemically induced carcinogenesis observed in regenerative organisms. Schmidtea mediterranea is, therefore, an ideal model to study pluripotent stem cell responses with stem cells residing in their natural environment.

Stem cell proliferation patterns as an alternative for in vivo prediction and discrimination of carcinogenic compounds.

One of the major challenges in the development of alternative carcinogenicity assays is the prediction of non-genotoxic carcinogens. The variety of non-genotoxic cancer pathways complicates the search for reliable parameters expressing their carcinogenicity. As non-genotoxic and genotoxic carcinogens have different cancer risks, the objective of this study was to develop a concept for an in vivo test, based on flatworm stem cell dynamics, to detect and classify carcinogenic compounds.