A family of therapeutic stem cells called multipotent adult progenitor cells (MAPC) may lessen the damage caused by the immune system’s damaging second-wave response to blunt-force blow injuries to the spinal cord, thereby preserving function that would otherwise be lost, according to research published in Scientific Reports, an online journal from the publishers of Nature.
After sensing a blunt-force injury to the spinal cord, the body dispatches macrophages to dispose of dead tissue. The macrophages also dispose of healthy tissue, resulting in a larger lesion size and additional loss of function.
To see if it would be possible to reduce lesion size and preserve function after a blunt-force injury to the spinal cord, researchers at Case Western Reserve University School of Medicine investigated whether adult bone marrow-derived stem cells, which exhibit immunomodulatory properties, could alter inflammation and promote recovery.
The researchers found that MAPCs were able to modulate the aggressive behavior of macrophages in lab animals. The macrophages still provided the necessary debris cleaning, but appeared less disruptive of healthy tissue.
“These were kinder, gentler macrophages,” Jerry Silver, PhD, professor of neurosciences at CWRU said in a statement. “They do the job, but they pick and choose what they consume. The end result is spared tissue. We don’t know what makes these nicer macrophages more subdued, but this is a subject we are researching in the lab.”
Research in the Silver lab also found that the timing of injecting MAPCs determined their effectiveness. The lab animals had a beneficial macrophage immune response that spared more spinal cord tissue and had markedly improved hind-paw motor control and urinary function. This occurred after the researchers injected MAPCs into these 1 day post-injury. The injection travelled primarily into their spleens, a reservoir for immature macrophages.