Pharmacological Effects on Ceroid Lipofuscin and Neuronal Structure in Cln3 ^∆ex7/8 Mouse Brain Cultures

Juvenile Batten disease (JBD) is an inherited disorder that is characterized by the development of blindness, seizures, and progressive motor, psychiatric, and cognitive impairment. A model of JBD expressing the predominant human mutation (Cln3 ^∆ex7/8 ) has been explored. Dissociated brain cultures from Cln3 ^∆ex7/8 knock-in mice were compared to wild type (WT) for effects on granules of ceroid lipofuscin (CL) and neuronal structure. Utilizing high content image analysis of CL granules identified with antibodies to mitochondrial ATP synthase subunit c or tripeptidyl peptidase-1, significant increases in the areas for both immunoreactive granules were observed in Cln3 ^∆ex7/8 cultures in comparison to WT. CL granules also exhibit autofluorescence at 488 and 560 nm, and the areas of these autofluorescent spots were found to be significantly increased in Cln3 ^∆ex7/8 cultures in comparison to WT. Progressive increases in CL granule area in Cln3 ^∆ex7/8 cultures were observed during culture development. Because current therapies for JBD provide only symptomatic support, a therapeutic strategy has been explored based on the observations that JBD-related tissues are deficient in β-galactosyl ceramide. Treatment of cultures for 40 h with a potent analog of β-galactosyl ceramide (SNB-4050) produced significant decreases in CL granule area in the Cln3 ^∆ex7/8 cultures; whereas identical studies on WT cultures produced no detectible changes. Significant decreases in average neurite length and neurite branch point number were also observed in the Cln3 ^∆ex7/8 cultures that were attenuated by treatment with 1 nM SNB-4050. These studies indicate Cln3 ^∆ex7/8 brain cultures may be useful to screen therapeutic agents for treatment of JBD.