PhD Scientific Days 2026

Poster Session 1.A - Molecular Medicine

Development of a pluripotent stem cell-derived organoid system for studying the molecular pathways of cerebellar ataxia

Name of the presenter

Sándor, Alexandra

Institute/workplace of the presenter

HUN-REN Research Centre for Natural Sciences, Institute of Molecular Life Sciences

Authors

Alexandra Fejes¹, Attila Karsai², Éva Bakos¹, Katalin Monostory¹, Kornélia Szebényi¹
1: HUN-REN Research Centre for Natural Sciences, Institute of Molecular Life Sciences
2: Microtrade 2002. Kft

Text of the abstract

The cerebellum is important for processing motor and sensory information. Due to its continoued development during the post-natal period, it is vulnerable to a number of pathological processes, for example to different type of ataxias. Spinocerebellar ataxias (SCA) represent a group of ataxias with a diverse range of neurological disorders, mainly characterised by the loss of motor co-ordination. Recently it has been discovered that pathological pathways of different genetic sub-types of SCA can overlap and they affect not only Purkinje cells, but also other cell types of the cerebellum. The human induced pluripotent stem cell (hiPSC)-derived cerebellar organoid system contains the disease relevant cell types in a tissue-like organization and therefore can provide a relevant model for investigating the molecular mechanisms of ataxias affecting the human cerebellum.
We developed a reproducible differentiation protocol for the generation of a hiPSC-derived organoid model of the cerebellum, which also enables the production of cerebellar organoids from hiPSC lines created from patients with SCA. We showed that Kirrel2-positive Purkinje progenitors appear already on day 35, from which Calbindin-positive Purkinje neurons develop by day 50. By optimizing the culture conditions, the later developing astroglial cells were already detectable on the 50th day. In order to prove that the model is also suitable for detecting pathological changes, we treated the organoids with IL-1β, capable of inducing ataxia in mice. IL-1β treatment increased the expression level of the autophagy marker P62. In order to find out whether this change occurred in a cell-specific manner, we examined P62 in organoid sections together with neuronal (MAP2) and astroglial (GFAP) markers.
Overall, it can be concluded that we have created an organoid model of the human cerebellum, which is suitable for examining cell-specific pathological changes and can serve as a platform for the development of therapies targeting them.
Project no. 2023-2.1.2-KDP-2023-00016 has been implemented with the support provided by the Ministry of Culture and Innovation of Hungary from the National Research, Development and Innovation Fund, financed under the KDP-2023 funding scheme.