Characterization of companion animal pluripotent stem cells.

Pluripotent stem cells have the capacity to grow indefinitely in culture and differentiate into derivatives of the three germ layers. These properties underpin their potential to be used in regenerative medicine. Originally derived from early embryos, pluripotent stem cells can now be derived by reprogramming an adult cell back to a pluripotent state. Companion animals such as horses, dogs, and cats suffer from many injuries and diseases for which regenerative medicine may offer new treatments. As many of the injuries and diseases are similar to conditions in humans the use of companion animals for the experimental and clinical testing of stem cell and regenerative medicine products would provide relevant animal models for the translation of therapies to the human field. In order to fully utilize companion animal pluripotent stem cells robust, standardized methods of characterization must be developed to ensure that safe and effective treatments can be delivered. In this review we discuss the methods that are available for characterizing pluripotent stem cells and the techniques that have been applied in cells from companion animals. We describe characteristics which have been described consistently across reports as well as highlighting discrepant results. Significant steps have been made to define the in vitro culture requirements and drive lineage specific differentiation of pluripotent stem cells in companion animal species. However, additional basic research to compare pluripotent stem cell types and define characteristics of pluripotency in companion animal species is still required. © 2017 International Society for Advancement of Cytometry.

Canine duplication of Descemet's membrane.

The morphology of a duplication phenomenon of the canine Descemet's membrane (DM) is described in relation to signalment, history, and ocular disease status. Sixty-six canine eyes from the Comparative Ocular Pathology Laboratory of Wisconsin archives between 2000 and 2007 were examined. All cases were stained with hematoxylin and eosin and Alcian blue periodic acid-Schiff (PAS), while 14 cases were additionally stained with Masson's trichrome, picrosirius red, cytokeratin AE1/AE3 (CK), vimentin, and alpha-smooth muscle actin (SMA). Transmission electron microscopy (TEM) examination was performed in 3 corneas and in 1 normal control eye. Alcian blue PAS staining and TEM confirmed the basement membrane nature of the abnormal secondary DM. The thickness of the first DM, referred to as the corneal layer (CL) and the second or anterior chamber layer (ACL), were nearly the same, with no significant difference seen (P = .93). In 39% (26/66) of the eyes, a fibrous, collagenous matrix component was present between the CL and ACL, which contains vimentin-positive and alpha-SMA-negative spindle cells (14/14).The corneal endothelial cells in 7/14 eyes stained weakly with CK and strongly in 2 additional eyes. The most frequent histopathologically confirmed, clinical ocular histories were chronic glaucoma in 76% (50/66) of eyes, previous intraocular surgery in 36% (24/66), lens luxation in 21% (4/66), and blunt trauma in 15% (10/66) of the cases. We speculate that activation and migration of endothelial cells, in association with trauma or lens contact, play a role in the pathogenesis of this phenomenon.