title: Progressive retinal degeneration and glial activation in the CLN6 (nclf) mouse model of neuronal ceroid lipofuscinosis: a beneficial effect of DHA and curcumin supplementation.
abstract: Neuronal ceroid lipofuscinosis (NCL) is a group of neurodegenerative lysosomal storage disorders characterized by vision loss, mental and motor deficits, and spontaneous seizures. Neuropathological analyses of autopsy material from NCL patients and animal models revealed brain atrophy closely associated with glial activity. Earlier reports also noticed loss of retinal cells and reactive gliosis in some forms of NCL. To study this phenomenon in detail, we analyzed the ocular phenotype of CLN6 (nclf) mice, an established mouse model for variant-late infantile NCL. Retinal morphometry, immunohistochemistry, optokinetic tracking, electroretinography, and mRNA expression were used to characterize retinal morphology and function as well as the responses of Müller cells and microglia. Our histological data showed a severe and progressive degeneration in the CLN6 (nclf) retina co-inciding with reactive Müller glia. Furthermore, a prominent phenotypic transformation of ramified microglia to phagocytic, bloated, and mislocalized microglial cells was identified in CLN6 (nclf) retinas. These events overlapped with a rapid loss of visual perception and retinal function. Based on the strong microglia reactivity we hypothesized that dietary supplementation with immuno-regulatory compounds, curcumin and docosahexaenoic acid (DHA), could ameliorate microgliosis and reduce retinal degeneration. Our analyses showed that treatment of three-week-old CLN6 (nclf) mice with either 5% DHA or 0.6% curcumin for 30 weeks resulted in a reduced number of amoeboid reactive microglia and partially improved retinal function. DHA-treatment also improved the morphology of CLN6 (nclf) retinas with a preserved thickness of the photoreceptor layer in most regions of the retina. Our results suggest that microglial reactivity closely accompanies disease progression in the CLN6 (nclf) retina and both processes can be attenuated with dietary supplemented immuno-modulating compounds.
authors.affiliation: Institute of Human Genetics, University of Regensburg, Regensburg, Germany ; Department of Ophthalmology, University of Cologne, Cologne, Germany.
authors.forename: Myriam
authors.initials: M
authors.lastname: Mirza
authors.forename: Cornelia
authors.initials: C
authors.lastname: Volz
authors.forename: Marcus
authors.initials: M
authors.lastname: Karlstetter
authors.forename: Monica
authors.initials: M
authors.lastname: Langiu
authors.forename: Aleksandra
authors.initials: A
authors.lastname: Somogyi
authors.forename: Mika O
authors.initials: MO
authors.lastname: Ruonala
authors.forename: Ernst R
authors.initials: ER
authors.lastname: Tamm
authors.forename: Herbert
authors.initials: H
authors.lastname: Jägle
authors.forename: Thomas
authors.initials: T
authors.lastname: Langmann
mesh_terms: D000818:Animals; D003474:Curcumin / Q000627:therapeutic use*; D004195:Disease Models, Animal; D004281:Docosahexaenoic Acids / Q000627:therapeutic use*; D051379:Mice; D009472:Neuronal Ceroid-Lipofuscinoses / Q000188:drug therapy* / Q000235:genetics / Q000378:metabolism; D012160:Retina / Q000187:drug effects / Q000473:pathology
chemical_list: D004281:Docosahexaenoic Acids; D003474:Curcumin