Neuronal Ceroid- Lipofuscinosis in Two Cats

MARK CHALKLEY – 3rd YEAR ANATOMIC PATHOLOGY RESIDENT

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 #1 Control

Cerebral Cortex

Normal Case #2Normal

H & EH & E

H & ELFB/ H&E

PASAF

Immunofluorescence

• Normal and abnormal

H & E GFAP

Normal Case #2

Lesion DistributionAnatomic Location Lipopigment/Ceroid Neuronal/ Cell Loss Gliosis

1 2 1 2 1 2

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

Disease Cause Organs affected Storage material

Special stains

Lectin histo-

chemistryEM

1. Ceroid-Lipofuscinoses

Unknown or lysosomal protein defects

Predominantly cerebrum, cerebellum & retina in cats but can be inmany tissues

Subunit c of mitochondrial ATPase, amyloid-β, precursor protein, SAPs

Magneta with PASLFB+Sudan black+Auto-fluorescent

Variable to nil reactivity

Curvilinear bodiesFingerprint profiles Granular osmophilic deposits

2. GangliosidosesLysosomal 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 macsPAS – in neuronsLFB+

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 Characteristic Lipofuscin Ceroid

Circumstance of deposition Aging Pathological

Location Lysosome Lysosome

Autofluorescence Positive Positive

Storage components

Protein Heterogenous mix, amyloid-β protein Subunit c of mitochondrial ATPase, amyloid-β, precursor protein, saposins

Lipids Triglycerides, FFA, dolichols Phosphorylated dolichols, phospholipids, neutral lipids

Carbohydrates Dolichol-linked oligosaccharides Dolichol-linked oligosaccharides

Metals Fe, Cu, Al, Zn, Ca, Mn Predominantly Fe

Histochemistry (including lectins)

Sudan Black Positive Positive

Luxol fast blue Positive Positive

PAS Positive Positive

Concanavalin A Positive Positive

Agglutinin Negative Positive

Ultrastructure

Granular osmophilic deposits Positive Positive

Fingerprint profiles Negative Positive

Curvilinear bodies Negative Positive

*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?