Applications of Placenta-Derived Cells in Veterinary Medicine

The field of regenerative medicine is moving toward clinical practice. In this context, domestic animals cover a dual role, acting as both patients and valuable translational models. The absence of regulatory and ethical guidance has encouraged rapid translation of unproven stem cell protocols in veterinary medicine. However, evidenced-based preclinical and clinical trials of stem cell therapies performed in domestic animal models are critical in advancing stem cell therapies. To this end, placenta-derived stem cells have been recently investigated in domestic animals, and a large amount of information has been obtained in regard to cell origin, isolation, enrichment, and processing. Aside from their high in vitro plasticity, four main characteristics of placenta-derived cells make them attractive candidates for therapeutic approaches: stemness features common to cells from large-sized mammals, low immunogenicity and immunomodulatory properties, multilineage regenerative capacity, and the successful engraftment and long-term survival in various host tissues after auto- or allo/xenotransplantation. Preclinical studies performed on experimental models, as well as clinical trials designed to treat spontaneous diseases, have demonstrated beneficial regenerative effects, particularly those exerted by amniotic-derived cells. These effects arise from a mutual tissue-specific cell differentiation (tendon- and bone-derived lineage cells), and paracrine secretion of bioactive molecules in host tissues that ultimately drive crucial repairing processes (e.g., anti-inflammatory, antifibrotic, angiogenic, and neurogenic). The knowledge acquired thus far on the mechanisms of action of placental-derived stem cells and on their effectiveness and safety in animal models highlights promising perspectives for the treatment of musculoskeletal disorders and widespread common and incurable pathologies affecting companion animals and humans.