Study of local anti-inflammatory properties of mesenchymal stem cells: treatment of equine foot and hoof lesions

Abstract

Mesenchymal stem cells (MSCs) are a promising tool for treatment of a variety of injuries and disorders because of their secretion of numerous bioactive molecules leading to tissue regeneration. The central nervous system (CNS) has a limited capacity for regeneration. As such, MSCs are being evaluated as a cell therapy for a number of chronic degenerative and inflammatory neurological conditions. Equine protozoal myeloencephalitis (EPM) and cervical vertebral stenotic myelopathy (CVSM) are common equine neurologic diseases where the standard of care therapy frequently does not result in full, functional recovery. The aims of this project are to better understand MSCs neurodifferentation and function in the context of normal and inflamed cerebrospinal fluid (CSF) and to determine if intrathecal allogeneic MSCs administration is safe in healthy horses. For this project we will have 2 parts. For the in vitro part (part 1), CSF from normal horses (n=5) and horses with EPM and CVSM (n=5) will be used. CSF will be evaluated for cellular and protein constituents. Additionally, we will evaluate bone marrow (BM)-MSCs response to co-incubation for 5 days with CSF by measuring MSCs viability, proliferation, immunomodulatory capacity and release of neurotrophic factors. Also, we will evaluate which source shows the best neurodifferentiation capacity in vitro (BM, n=3; adipose tissue (AT), n=3 or umbilical cord (UC), n=3). For the second part of the study, we will evaluate the feasibility and safety of intrathecal allogenic MSCs transplantation into healthy horses (n=6). Allogeneic BM-MSCs will be used for inoculation. Horses will be injected with 100x106 MSCs via lumbosacral (LS, n=3) and atlanto-occipital (AO, n=3). For a subset of these horses, MSCs will be radiolabelled with technetium prior to LS (n=1) and AO (n=1) injections. Scintigraphy will be performed on these 2 horses at 0, 1, 6, and 24 hours after injection. Blood samples and CSF will be collected prior to and after MSCs injection (day 0 and day 30). Complete neurological clinical examinations will be performed twice a week for 30 days after MSC administration. This study may help to understand the mechanisms by which MSCs work in CNS diseases. Additionally, if MSCs administration is well-tolerated in healthy horses these data would provide critical justification for the administration of MSCs to client-owned horses that present with EPM and CVSM neurologic sequelae secondary to poorly-responsive to standard therapy. (AU)