Exogenous Flupirtine as Potential Treatment for CLN3 Disease.

Katia Maalouf,Sara Saab,Paul C Trippier,Joelle Makoukji,Angelica V Carmona,Noël Ghanem,Nadine J Makhoul,Rose-Mary Boustany,Nihar Kinarivala

doi:10.3390/cells9081872

Abstract

CLN3 disease is a fatal neurodegenerative disorder affecting children. Hallmarks include brain atrophy, accelerated neuronal apoptosis, and ceramide elevation. Treatment regimens are supportive, highlighting the importance of novel, disease-modifying drugs. Flupirtine and its new allyl carbamate derivative (compound 6) confer neuroprotective effects in CLN3-deficient cells. This study lays the groundwork for investigating beneficial effects in Cln3Δex7/8 mice. WT/Cln3Δex7/8 mice received flupirtine/compound 6/vehicle for 14 weeks. Short-term effect of flupirtine or compound 6 was tested using a battery of behavioral testing. For flupirtine, gene expression profiles, astrogliosis, and neuronal cell counts were determined. Flupirtine improved neurobehavioral parameters in open field, pole climbing, and Morris water maze tests in Cln3Δex7/8 mice. Several anti-apoptotic markers and ceramide synthesis/degradation enzymes expression was dysregulated in Cln3Δex7/8 mice. Flupirtine reduced astrogliosis in hippocampus and motor cortex of male and female Cln3Δex7/8 mice. Flupirtine increased neuronal cell counts in male mice. The newly synthesized compound 6 showed promising results in open field and pole climbing. In conclusion, flupirtine improved behavioral, neuropathological and biochemical parameters in Cln3Δex7/8 mice, paving the way for potential therapies for CLN3 disease.

Highlights

The neuronal ceroid lipofuscinoses (NCLs) constitute a family of fatal pediatric neurodegenerative disorders that primarily affect the central nervous system (CNS) [1]
Open field behavioral testing showed that vehicle-treated Cln3∆ex7/8 mice exhibit increased spontaneous locomotor activity compared to vehicle-treated WT controls in both genders at 15 weeks of age
Vehicle-treated Cln3∆ex7/8 mice were significantly more mobile than their vehicle-treated WT littermates (Figure 2A,B). These results indicate that WT mice display increased anxiety-like behavior when put in the novel test environment compared with Cln3∆ex7/8 mice

Summary

Introduction

The neuronal ceroid lipofuscinoses (NCLs) constitute a family of fatal pediatric neurodegenerative disorders that primarily affect the central nervous system (CNS) [1]. NCLs are atypical lysosomal storage disorders that manifest accumulation of lipopigments in the lysosomes of neurons and other. CLN3 disease arises due to mutations in the CLN3 gene and is the most common variant of the NCL group [3]. This neurological disease manifests at four to eight years of age with progressive visual deterioration, seizures, blindness, motor and cognitive decline, mental retardation, epilepsy and early death during the second or third decade of life [4]. Eighty five per cent of patients with CLN3 disease harbor a 1.02 kb deletion eliminating exons 7/8 and creating a truncated CLN3 protein [7,8]

Methods

Results

Discussion

Conclusion