Visualizing the DNA Damage Response in Purkinje Cells Using Cerebellar Organotypic Cultures.

Abstract

Cerebellar Purkinje cells (PCs) exhibit a unique interplay of high metabolic rates, specific chromatin architecture, and extensive transcriptional activity, making them particularly vulnerable to DNA damage. This necessitates an efficient DNA damage response (DDR) to prevent cerebellar degeneration, often initiated by PC dysfunction or loss. A notable example is the genome instability syndrome, ataxia-telangiectasia (A-T), marked by progressive PC depletion and cerebellar deterioration. Investigating DDR mechanisms in PCs is vital for elucidating the pathways leading to their degeneration in such disorders. However, the complexity of isolating and cultivating PCs in vitro has long hindered research efforts. Murine cerebellar organotypic (slice) cultures offer a feasible alternative, closely mimicking the in vivo tissue environment. Yet, this model is constrained to DDR indicators amenable to microscopic imaging. We have refined the organotypic culture protocol, demonstrating that fluorescent imaging of protein-bound poly(ADP-ribose) (PAR) chains, a rapid and early DDR indicator, effectively reveals DDR dynamics in PCs within these cultures, in response to genotoxic stress.