Combination of cell transplantation and glial cell line-derived neurotrophic factor-secreting encapsulated cells in Parkinson's disease

A major limitation of cell transplantation for Parkinson's disease (PD) is the mediocre survival of the grafted cells. Facilitating graft survival may improve the functional outcomes of the transplanted cells. Here, we discuss our observations that combination of rat fetal ventral mesencephalic (VM) tissue and encapsulated cells that secrete glial cell line-derived neurotrophic factor (GDNF) enhanced graft function in an animal model of PD. We described significant 2-fold increase in the number of tyrosine hydroxylase immunoreactive (TH-ir) cells per graft, as well as 1.7-fold and 9-fold increments in TH-ir fiber outgrowth into the host brain and toward the capsule with combined transplants and GDNF capsules as opposed to the VM transplants and mock-capsule group. These findings demonstrate that encapsulated GDNF-secreting cells improve graft survival that may optimize functional benefits for the treatment of PD.