GROWTH FACTOR-INDUCED NEURITE GROWTH IN PRIMARY NEURONAL CULTURES OF DOGS WITH NEURONAL CEROID-LIPOFUSCINOSIS

Neuronal ceroid lipofuscinosis (NCL) is a type of lysosomal storage di sease resulting in the progressive deterioration of neuronal function. Little is known about the genetics, pathophysiology and biochemical b asis of this disease. This is, in part, due to the complexity of the c entral nervous system and the lack of an in vitro model. In this repor t, we describe the conditions to establish neuronal cells in primary c ulture from the brains of newborn English setters with NCL, a canine m odel for this disease. Over 80% of the neuronal cells from normal dog brain establish well-developed interconnecting networks of long neurit es. On the contrary, approximately 50% of the neurons cultured from NC L dog brains do not assemble neurites. Of those NCL neurons with proce sses, the neurites are routinely shorter and fewer in number than thos e seen in normal cultures. In addition, the characteristic inclusion b odies, pathological markers for this disease in vivo, are prevalent in the soma of cultured neuronal cells isolated from NCL dog brain. A ti me-dependent maturation of the inclusion bodies suggests a progression of the disease state in culture. The reduced ability of the NCL neuro ns to establish neurites prompted us to examine the effects of growth factors on neurite assembly. Our data show that insulin-like growth fa ctor I, epidermal growth factor and platelet-derived growth factor are capable of stimulating neurite outgrowth of NCL neurons. We report th e establishment and morphological characterization of neuronal culture s from normal and NCL dog brains. The abnormal morphology of cultured NCL neurons can, in part, be alleviated by supplementing the medium wi th growth factors. The results suggest that this cellular model of NCL will be useful to study the molecular and physiological mechanisms of NCL disease, as well as to test potential therapeutic agents and cand idate genes.