Dec. 11, 2009
An international research team has published results showing that injection of bone marrow adult stem cells into the brain can ameliorate effects of Alzheimer's disease in a mouse model of the disease. Injection of bone marrow mesenchymal stem cells reduced deposition of the protein found in Alzheimer plaques, decreased inflammatory responses often associated with the disease, and improved cognitive function. The results are encouraging, though still a long ways from clinical application.
Earlier this year scientists at UC-Irvine showed that neural stem cells could rescue memory in a mouse model of Alzheimer's disease. Their published results indicated that the adult stem cells helped protect neural connections in the brain by secreting a factor called brain-derived neurotrophic factor (BDNF). Lead author Matthew Blurton-Jones noted:
"If you look at Alzheimer's, it's not the plaques and tangles that correlate best with dementia; it's the loss of synapses connections between neurons. The neural stem cells were helping the brain form new synapses and nursing the injured neurons back to health."
Similar results were published by researchers at the University of South Florida in July. They found that a human growth factor that stimulates blood stem cells to proliferate in the bone marrow reverses memory impairment in Alzheimer's mice. The protein factor mobilized blood stem cells in the bone marrow and neural stem cells within the brain and both of these actions led to improved memory and learning behavior in the Alzheimer's mice.
"The concept of using GCSF to harness bone marrow-derived cells for Alzheimer's therapy is exciting and the findings in mice are promising, but we still need to prove that this works in humans," said Dr. Raj, a physician researcher at the Byrd Alzheimer's Center at USF Health.
Based on their promising findings with mice, the researchers are doing a randomized, controlled clinical trial to test the safety and effectiveness of the treatment in 12 patients with mild to moderate Alzheimer's disease.