Evaluation of chip-reprogrammed iPSCs for cell replacement therapy for Parkinson’s disease

Sammanfattning

Parkinson’s disease (PD) is a progressive neurodegenerative disease, characterized by degeneration of dopaminergic neurons, leading to notable difficulties with one’s movement. Among different treatment options, stem cell replacement therapies have been recognized as an option to not only treat disease symptoms but to address its underlying cause- neuronal degeneration. This can be achieved through the implantation of neuronal progenitor cells derived from stem cells. Human induced pluripotent stem cells (iPSCs) offer a promising source for autologous cell therapies in neurodegenerative diseases such as PD, as they raise fewer ethical concerns and eliminate the need for a patient to be immunosuppressed compared to embryonic stem cells (ESCs). The workflow to reprogram somatic cells into iPSCs and subsequently iPSCs into ventral midbrain (VM) mesencephalic dopaminergic (mesDAergic) progenitor is labour-intensive, time-consuming and expensive; therefore, there is a critical need for improving the manufacturing process. Reprogramming with the use of a microfluidic device offers an automated and scalable alternative to manual iPSC generation. In this study, efficiency and consistency in generating ventral midbrain (VM) mesencephalic dopaminergic (mesDAergic) progenitor cells from chip-reprogrammed iPSCs were evaluated. Two donor-derived iPSC lines reprogrammed using either conventional or chip-based (microfluidic) methods served as a pluripotent starting point for differentiation into mesDAergic progenitor cells through controlled exposure to specific developmental cues. The goal was to assess if reprogramming method used compromises the quality of the differentiation protocol outcome. Additionally, we investigated the potential differences that might be related to donor sources. Two donor-derived lines were subjected to differentiation into VM mesDAergic progenitors. One of two tested lines demonstrated comparable differentiation potential across both reprogramming methods. Subsequently, conventionally and chip-reprogrammed cells of this cell line were successfully differentiated into mature neurons. Those results were analysed based on the detection of specific VM mesDAergic progenitor markers as well as mature neuronal markers. The other tested line failed to differentiate into VM mesDAergic progenitors, when reprogrammed conventionally but succeeded when reprogrammed using the chip platform. It may be an indication of donor-related variability or method-dependent reprogramming efficiency. However, it is not easy to understand the interaction between the reprogramming method, donor background and other sources of variability and to point out one specific reason for such an outcome. Achieving this could bring us closer to the widespread use of iPSCs, enabling personalized medicine to prevent or reverse conditions like Parkinson’s disease, diabetes, spinal cord injuries, and others.