Jared Ehrhart from the University of South Florida, who also serves as the Director of Research and Development at Saneron CCEL Therapeutics Inc, and his coworkers have shown that cells from umbilical cord blood can not only improve the health of mice that have an experimental form of Alzheimer’s disease (AD), but these can also be administered intravenously, which is safer and easier than other more invasive procedures.
Laboratory mice can be engineered to harbor mutations that can cause a neurodegenerative disease that greatly resembles human AD. One such mouse is the PSAPP mouse that harbors two mutations that are known to cause an inherited, early-onset form of AD in humans. By placing both mutations in the same mouse, the animal forms the characteristic protein plaques more rapidly and shows significant AD symptoms and brain pathology.
Ehrhart used PSAPP mice to test the ability of human umbilical cord blood to ameliorate the symptoms of AD. He injected one million Human Umbilical Cord Blood Cells (HUCBCs) into the tail veins of PSAPP mice and 2.2 million into the tail veins of Sprague-Dawley rats. Then he harvested their tissues at 24 hours, 7 days, and 30 days after injection. Then Ehrhart and his team used a variety of techniques to detect the presence of the HUCBCs.
Interestingly, the HUCBCs were able to cross the blood-brain barrier and take up residence in the brain. The cells remained in the brain and survived there for up to 30 days and did not promote the growth of any tumors.
Several studies have shown that the administration of HUCBCs to mice with a laboratory form of AD can improve the cognitive abilities of those mice (see Darlington D, et al., Cell Transplant. 2015;24(11):2237-50; Banik A, et al., Behav Brain Res. 2015 Sep 15;291:46-59; Darlington D, et al., Stem Cells Dev. 2013 Feb 1;22(3):412-21). However, in such cases it is essential to establish that the administered cells actually found their way to the site of damage and exerted a regenerative response.
Even though Ehrhart and his troop found that the intravenously administered HUCBCs were widely distributed throughout the bodies of the animals, they persisted in the central nervous system for up to one month after they were injected. In the words of this publication, which appeared in Cell Transplantation, the HUCBCs were “broadly detected in both in the brain and several peripheral organs, including the liver, kidneys, and bone marrow.”. The fact that such a minimally invasive procedure like intravenous injection can effectively introduce these cells into the bodies of the PSAPP mice and still produce a significant therapeutic effect is a significant discovery.
Ehrhart and his colleagues concluded that HUCBCs might provide therapeutic effects by modulating the inflammation that tends to accompany the onset of AD. Furthermore, these cells do not need to be delivered by means of an invasive procedure like intracerebroventricular injection. Furthermore, even though HUCBCs were detected in other organs, their numbers in those places was not excessive and the ability of the HUCBCs to cross the blood-brain barrier suggests that these cells might serve as safe, effective therapeutic agents for AD patients some day.