Assistant Research Fellow Department of Medical Research, Buddhist Tzu Chi General Hospital Hualien City, United States
Abstract: Human induced pluripotent stem cell (iPSC) is a promising source of midbrain dopaminergic progenitor (mDAp) for Parkinson’s disease (PD) transplantation. However, current mDAp are unavailable to overcome the clinical challenges, including undifferentiated stem cell-associated tumorigenicity, limited efficacy of in vitro mDAp production, and delayed differentiation and maturation efficacy of mDAp in vivo. Here, we first applied n-butylidenephthalide, a chemical compound, to selectively reduce undifferentiated iPSCs and consequently promote neurite formation. Additionally, we introduced a novel set of patterning factors, including a transient high concentration of a GSK-3β inhibitor, to efficiently convert iPSCs into mDA neurons. With these improved techniques, 75% of iPSCs robustly differentiated into mature mDA neurons, showing burst dopamine secretion and phasic electrophysiological activities with external stimuli. To evaluate the therapeutic potential, cryopreserved mDAp were transplanted into 6-OHDA PD rats. No teratoma or neural tumor was observed within 26 weeks post-implantation. Surprisingly, within just eight weeks post-transplantation, mDAp survived and robustly differentiated into mDA neurons in the injected striatum, leading to significant functional recovery. These preclinical findings demonstrate that our reproducible and innovative process produces high-quality off-the-shelf mDAp, potentially enhancing safety and reducing the nonreactive window in iPSC-treated PD patients.
Funding Source: National Science and Technology Council of Taiwan (MOST 110-2314-B-303-017-MY3 and NSTC 113-2314-B-303-024-, Dr. S.-Z.L.); (MOST 111-2314-B-303-027-MY2 and NSTC 113-2314-B-303-026-, Dr. C.-Y.C.)
