Georgia Veterinary Scholar	Faculty Mentor
Lindsay Boozer University of Georgia Class of 2008	Dr. Tom Krunkosky

Equine Laminitis: Matrix Metalloproteinase (MMP) Activity in Laminar and Skin of Clinical and Experimental Laminitis Subjects.

Lindsay Boozer*, Laura Riggs 1, Emily Chambers, Tom Krunkosky. Department of Anatomy and Radiology and Department of Large Animal Medicine 1, College of Veterinary Medicine, University of Georgia, Athens, GA 30602,

Laminitis is a common and debilitating disease in the horse posing unique problems for the veterinary community. The disease evolves from multiple etiologies; recently, matrix metalloproteinases (MMPs) have been implicated as a possible contributing factor to this disease. MMPs are zinc-containing, calcium-dependent proteases responsible for normal maintenance of the extracellular matrix throughout the body, including the equine hoof. They are present in normal laminar tissue and are involved in growth and remodeling of the hoof. Increased activity of two members of the matrix metalloproteinase family, MMP-2 and MMP-9, have been documented in acute and chronic laminitis causing a breakdown of the laminar basement membrane through increased proteolytic activity. The hoof is a structural modification of the integument and therefore, similar early inflammatory events leading to the development of laminitis may occur in the skin as well as the more specialized laminar tissue. Similarities between the physiology of the skin and laminar tissues are well documented but, at present, the use of the skin to study chronic laminitis is a novel approach. The objective of this project is to develop a better understanding of the similarities between the skin and lamina in normal animals, experimentally induced laminitic animals, and chronic laminitic animals by comparing relative amounts of matrix metalloproteinases present in each group. Skin and laminar tissues were taken from three groups of equine subjects: a control group, an experimentally induced laminitis group and a group of horses donated to UGA with histories of chronic laminitis. Skin and laminar tissue from each subject were homogenized and sonicated. Each sample was separated using gelatin zymography on 8% SDS-PAGE gels and analyzed using a Fluor-S Max2 MultiImager system (Bio-Rad, Richmond , CA ) and associated software. This study will determine normal MMP ranges for control and laminitic horses, and will compare the relative amounts of MMPs in tissues across all groups. The project will benefit equine veterinarians and researchers as a potential new and less invasive approach to the study of laminitis, a frequently diagnosed but still not well understood disease process.

Funded by American Quarter Horse Association