Systemic human CD34+ cells populate the brain and activate host mechanisms to counteract nigrostriatal degeneration

Aim: Here we investigated the neuroprotective potential of systemic CD34+ human cord blood cells (hCBCs) in a 6-hydroxydopamine rat model of Parkinson's disease. Methods: Purified CD34+ hCBCs were intravenously administered to rats subjected to 6-hydroxydopamine 24 h earlier, and behavioral and immunohistological analysis performed. Results: CD34+ hCBC administration significantly prevented host nigrostriatal degeneration inducing behavioral recovery in treated rats. Although donor hCBCs did not differentiate into neural phenotypes, they stimulated the production of new neuroblasts and angiogenesis, and reduced gliosis in recipient animals. Importantly, surviving donor hCBCs were identified, and their tissue distribution pattern correlated with the observed therapeutic effects....