Co-cultivation of Niemann-Pick disease type C fibroblasts belonging to complementation groups alpha and beta stimulates LDL-derived cholesterol esterification.

Niemann-Pick disease type C (NPC) is a neurovisceral storage disorder with an unknown primary deficiency. Somatic cell hybridization experiments using human cultured fibroblasts have shown that two complementation groups (NPC-alpha and NPC-beta) are associated with the biochemical and clinical phenotypes comprising NPC. We identified the rarer complementation group NPC-beta originally using the technique of filipin staining as a marker for complementation. In this study we show that the esterification of cholesterol derived from the LDL pathway can be used as an isotopic assay. However, multinuclear hybrids exhibit a delayed induction in this pathway. Furthermore, we discovered that, in the presence of an LDL source, co-cultivation of fibroblasts belonging to NPC-alpha and NPC-beta stimulated cholesterol esterification.