Human immune-cell response towards diverse xenogeneic and allogeneic decellularized biomaterials.

Background: Immunological knowledge on processed biological implants and mesh-prostheses is still mainly based on animal models, lacking information on the species-specific human immune response. We hypothesized that in contrast to human tissue even decellularized xenogenic specimens would lead to significant and tissue source dependent human immune reactions.

Methods: Specimens from processed allogenic and xenogenic pulmonary arteries, pericardium or dermis, were co-cultured with human peripheral blood mononuclear cells (PBMNC).

Ursolic acid causes DNA-damage, p53-mediated, mitochondria- and caspase-dependent human endothelial cell apoptosis, and accelerates atherosclerotic plaque formation in vivo.

Objective: The plant derived triterpene ursolic acid (UA) has been intensively studied in the past; mainly as an anti-cancer compound and for its cardiovascular protective properties. Based on the controversy of reports suggesting anti-angiogenic and cytotoxic effects of UA on one side and cardiovascular and endothelial protective effects on the other side, we decided to assess UA effects on primary human endothelial cells in vitro and atherosclerotic plaque formation in vivo.

Methods And Results: Our in vitro analyses clearly show that UA inhibits endothelial proliferation and is a potent inducer of endothelial cell death.