Neuronal Ceroid- Lipofuscinosis in Two Cats M ARK C HALKLEY – 3 rd Y EAR A NATOMIC P ATHOLOGY R ESIDENT

History & Signalment Similar history and signalment for both case #1 and #2: - Both between 1 or 2-years old male DSH cats - Submitted to animal shelters as strays with no previous history - Prolonged, progressive history of visual dysfunction (running into walls, difficulty tracking moving objects) and neurological deficits (falling, frantic running, behavior abnormalities) Both euthanized and submitted for necropsy

Case #1Control

Cerebral Cortex

NormalCase #2Normal

H & E

LFB/ H&E PASAF

Immunofluorescence Normal and abnormal

H & E GFAP

NormalCase #2

Lesion Distribution Anatomic LocationLipopigment/CeroidNeuronal/ Cell LossGliosis Cerebral cortex Thalamus Hypothalamus Basal Nuclei Hippocampus Cerebellum Spinal Cord Retina Extra-CNS tissues * + = mild, ++ = moderate, +++ = severe; 1 = Case No. 1; 2 = Case No. 2

DiseaseCauseOrgans affected Storage material Special stains Lectin histo- chemistry EM 1. Ceroid- Lipofuscinoses Unknown or lysosomal protein defects Predominantly cerebrum, cerebellum & retina in cats but can be in many tissues Subunit c of mitochondrial ATPase, amyloid-β, precursor protein, SAPs Magneta with PAS LFB+ Sudan black+ Auto- fluorescent Variable to nil reactivity Curvilinear bodies Fingerprint profiles Granular osmophilic deposits 2. Gangliosidoses Lysosomal enzyme deficiency CNS, PNS, liver, kidney, lymph n., cardiac Purkinje cells Glyco- sphingolipids PAS+ LFB+ Sudan black+ O-linked Membranous cytoplasmic bodies and/or zebra bodies 3. Gluco- cerebrosidoses Gluco- cerebrosidase deficiency CNS, macrophages (esp liver, LNs) Gluco- cerebrosides PAS+ in macs PAS – in neurons LFB+ O-linked Twisted, branching tubules or zebra bodies in neurons 4. Mannosidosis (glycoproteinosis) Lysosomal α or β mannosidase or α-L-fucosidase deficiency Many cells (neurons, epithelium, endothelium, mesenchyme) Carbohydrate (saccharides with mannose residues) PAS+, diastase resistant, Variably alcian blue+ N-linked Membrane bound vesicles, with floccular material & fine membrane stacks 5. Muco- polysaccharidoses (MPS VII in cats) Various enzyme deficiencies Predominantly bone and other connective tissues, neurons Gluco- aminoglycan Variable PAS+ LFB+ Sudan black+ Auto- fluorescent N-linked Empty vesicles, or floccular material /zebra bodies

Gangliosidoses Mannosidoses Ceroid-lipofuscinosis Sphingolipidoses & Mucopolysaccharidoses

Diagnosis Brain, spinal cord, eyes: Degenerative lysosomal storage encephalo- myelopathy and retinopathy, widespread, marked, chronic, with neuronal loss and astrogliosis - Consistent with neuronal ceroid-lipofuscinosis (NCL)

Lysosomal Storage Diseases (LSD) What is LSD anyway? LySergic acid Diethylamide Lumpy Skin Disease Lichenoid-pSoriasiform Dermatoses Louisiana School for the Deaf

NCL in Animals and Humans Four main variants – infantile, late-infantile, juvenile, adult 160 mutations in 10 human genes (CLN1-10) Lead to defects in 8 known proteins Gene defects also recognized in dogs, sheep and cattle Similar distribution and character of lesions & material Main storage material in animals and humans - subunit c of mitochondrial ATP synthase (SCMAS) or sphingolipid activator proteins A and D (SAPs) A correlation between the age of clinical onset of disease, ultrastructure of the storage material and the variants of NCL has not been established in animals

Lipofuscin vs Ceroid *Table adapted from SS Seehafer, DA Pearce, Neurology of Aging 27 (2006), p580.

Mechanisms of Ceroid Accumulation Seehafer S & Pearce D (2007) Autophagy Oxidation Lysosomal Function

Acknowledgements ACVP/STP coalition fellowship Pfizer & Dr Peter Schmidt University of Minnesota – - Dr Anibal Armien & Dr Gerry O’Sullivan - Electron microscopy laboratory

Questions?