The researchers confirmed that the remarkable increase in the numbers of fused cells was related to inflammation by using the traditional radiation/bone marrow transplant approach in mice with dermatitis. Finally, they counted the fused cells that formed in a mouse model of multiple sclerosis - an autoimmune disease characterized by inflammation and damage of the central nervous system. Neurologist and multiple sclerosis specialist Lawrence Steinman, MD, professor of neurology and neurological sciences at the medical school, co-authored the research and provided the mouse model for study. Heterokaryons in some of these mice numbered in the thousands.
Even more intriguing than the inflammation-induced increase in numbers was a cross-species experiment that showed nuclei from rat blood stem cells that had fused to Purkinje cells in mice stop expressing blood cell proteins and begin to express rat neuron-specific gene products. This switch exemplifies a type of genetic reprogramming that has been a source of ongoing debate and great interest in the world of stem cell research. Such reprogramming is critical to the regeneration of functional tissues by stem cells.
"What we're seeing is that this phenomenon is happening in real life," said Blau, who next plans to study whether such fusions can rescue damaged or dying Purkinje neurons. "We don't know yet if this function is beneficial, but we now know that there are sites where it happens at fairly high fre
|Contact: Mitzi Baker|
Stanford University Medical Center