Pericytes in Veterinary Species: Prospective Isolation, Characterization and Tissue Regeneration Potential

Although pericytes have long been known for their roles in blood vessel regulation, it was not until a decade ago that their tissue regeneration potential began to be considered, after studies showed that pericytes were the in vivo counterparts of mesenchymal stem/stromal cells (MSCs). The prospective isolation and culture expansion of pericytes brought great excitement as it opened the way to the therapeutic use of well-defined cell populations with known regenerative potential to overcome concerns associated with the use of traditional MSC preparations. Studies first in humans and later in the horse and other domestic species showed that indeed cultured pericytes had key characteristics of MSCs, namely, their immuno-phenotype and the abilities to grow clonally and to differentiate into mature mesenchymal cells both in vitro and vivo. Several studies with human pericytes, and to a much lesser extent with animal pericytes, have also shown significant promise in tissue repair in different disease models. This review summarizes current knowledge on the tissue regeneration properties of pericytes from domestic animals and outlines future steps necessary for realizing their full potential both in clinical veterinary medicine and in preclinical testing of human therapies using large animal models, including the need for robust approaches for isolation, culture and appropriate in vivo testing of the tissue regenerative properties of pericytes in these species.