STEM CELLS ISSUE 15.qxd:Jerkins feature.qxd
27/1/10
15:36
Page 2
STEM CELLS
I was asked to write this article the day before a child on a bicycle plowed into me, writes Niki Luciani (née Sweetnam), severing the tendon in my right leg. While human beings can be encased in plaster and given a set of crutches to hobble about on for a few months, horses cannot. Forty-eight hours after my accident I heard of a man in Greece who had suffered multiple heart problems and as a result had to have a special pump implanted in his heart to circulate the blood necessary to keep him alive. The medical team then injected stem cells into the muscle tissue to encourage repair so that the heart would eventually regain sufficient strength enough to function properly again.
A
N ITALIAN research team has just published a pioneering study of how equine stem cells can best be isolated, cultured and subsequently subdivided for diverse usage to best advance current veterinary treatments for the horse. Equine theriogenologist Professor Gaetano Mari, from the University of Bologna, leads a nine-strong team of specialists who are conducting research in an area of veterinary medicine which is rapidly changing the way equine injuries are treated, and, despite ethical and moral issues surrounding the use of human stem cells, is also rapidly changing the face of human medicine. Their research is being funded by the MIUR (Ministero dell’Istruzione, dell’Università e della Ricerca), which is the Italian Ministry for Education and Research. While traditional medicine has been based on improving surgical techniques and trialing and refining the use of drugs, stem cell therapy was first used back in the 1950s when human bone marrow transplants were trialed to cure leukemia sufferers. Stem cell therapy can be defined as the stimulation of previously irreparable organs to heal themselves by stimulating the growth of living tissues to repair or even replace damaged tissues and organs. It thus can be used to treat everything from laminitis to a fractured cannon bone to a weakened heart muscle to a simple skin lesion that refuses to heal. This is an area of medicine that is progressing so rapidly that by the time this article goes to press there will already have been further advancements, such as the use of platelet rich plasma, which is the isolation of platelets from a concentrated blood sample which are then introduced to the injury site, where they release growth factors to speed up repair, a treatment still very much in its infancy. The Bologna team
is one of a number of researchers worldwide racing to make the next breakthrough in stem cell medicine. Compared to human bone marrow transplants, the use of mesenchymal stem cells (a type of adult stem cell) in the repair of injuries in the horse is a recent field of veterinary therapy that has seen marked reductions in repair time and injury recurrence in the last decade. The high propensity for horses and particularly Thoroughbred racehorses to incur serious tendon lesions that necessitate long rest periods not suited to their hot blood means that there has been no shortage of “guinea pigs.” Even though the injury may be a straightforward and very common one, the complications that stall rest imposes both mentally and physically on a Thoroughbred often turn the treatment time on its head and lead to secondary problems that become insurmountable, such as the welldocumented onset of laminitis in the supporting limb in the case of Barbaro. For Barbara Merlo, a key member of the research group
those managing equine athletes it is not just the speed of the recovery time that matters, it is the quality of this time, and the quality of the repaired damage, too. The tendon must regain full elasticity and the tendon fibers their full strength; a measure of the success of stem cell therapy can be said to be the low recurrence rate of such injuries. Most mesenchymal stem cells, while found in a variety of different body tissues, are generally isolated from bone marrow or adipose tissue for clinical purposes and have the potential to develop the characteristics of bone, cartilage, muscle or tendon once planted in the seat of injury. However, their quality and quantity decrease with age as does their potential to transform into the specific kind of cell necessary to repair an injury site. The further disadvantage is that isolating bone marrow from a 3-year-old Thoroughbred is not the most straightforward of tasks! This means that alternative sources of stem cells have been sought with the focus on embryonic stem cells which derive directly from the embryo and umbilical cord blood. At the University of Bologna, Professor Mari’s research team has been working for months on a method of isolating stem cells from amniotic fluid, the birth membrane (placental tissues), the umbilical cord, and Wharton’s jelly (a glutinous substance found within the umbilical cord and a rich cell source) without adverse consequences on the health and well-being of either the mare or the newborn foal because they can be obtained non-invasively. Further isolation of stem cells with very similar qualities to mesenchymal stem cells from those collected at birth from the mare and foal has been difficult in that not enough can be isolated in a sufficiently sterile environment, but it is these placentalderived cells that have greater potential for growth and diversification than cells derived from other tissues or at a later stage in a horse’s life.
ISSUE 15 TRAINERMAGAZINE.com 37