Stroke is the second largest cause of death worldwide and the leading cause of long-term neurological disability. Therapies for stroke victims are improving, but remain hampered by the limited repair capacity of nerves in the brain and the unique properties of brain vasculature. Akihiko Taguchi and colleagues, of the National Cardiovascular Center in Japan, make great strides in providing new means to aid stroke victims with their current work showing that intravenous injection of specific immune cells called CD34+ cells after stroke greatly enhances nerve restoration in the region of damage in mice. The authors isolated CD34+ cells from human cord blood and injected them into mice within 48 hours of a stroke. These mice experienced increase new blood vessel growth in stoke-damaged region. The CD34+ cells also produced growth factors to aid in neural regeneration. There was also evidence of migration of nerve progenitors into the region of stroke damage. The mice that were treated with CD34+ cells showed improved behavioral characteristics. Of note, if blockers to blood vessel growth were given in addition to the CD34+ cells, all of the benefits of CD34+ treatment were lost. These data provide direct evidence that new blood vessel growth is essential for repairing stroke damage, and provide important information for investigating therapies for this deadly and debilitating affliction.
An accompanying commentary by Daniel Peterson, of the Rosalind Franklin University of Medicine and Science, places these data into the context of the difficulties of treating stroke victims, and what additional information beyond this study is required to best understand how these data will be useful for understanding and treating stroke patients.
TITLE: Administration of CD34+ cells after stroke enhances neurogenesis via angiogenesis in a mouse model