PhD Scientific Days 2025

Poster Session II. - B: Molecular Medicine

Development of a cerebellar organoid platform for investigating ataxia related molecular pathomechanisms

Name of the presenter

Sándor Alexandra

Institute/workplace of the presenter

HUN-REN TTK

Authors

Alexandra Sándor¹, Kornélia Szebényi¹

1: HUN-REN TTK

Text of the abstract

Spinocerebellar ataxias (SCA) represent a diverse range of neurological disorders, mainly
characterised by the slow degeneration of the cerebellum resulting in loss of motor co-ordination.
Given the distinct development, cell composition and size of the human cerebellum compared to
mice, human model systems are essential for studying neurodegenerative changes underlying
SCAs. Human induced pluripotent stem cell (hiPSC)-derived cerebellar organoid systems contain
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 have developed a protocol for the generation of a hiPSC-derived organoid model of the
cerebellum. The cell types found in the organoids on days 35, 50, 75 and 120 of the differentiation
were characterized by immunocytochemical methods, using markers specific to the developmental
stages of the cerebellum. We showed that Kirrel2-positive Purkinje progenitors appear on day 35,
from which Calbindin-positive Purkinje neurons develop by day 50. At this point astroglial cells
are also present in the cerebellar organoids. 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 evoked ER stress and increased the expression level of the ubiquitin-binding
protein P62.
In summary, 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.
Acknowledgement: We are greatful to Katalin Monostory and Ágota Apáti for providing laboratory spaces
and access to essential equipment. 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.