Korean researchers managed to identify the cause behind an early childhood disease that degrades the nervous system, the Ministry of Science, ICT and Future Planning said Tuesday.

According to the ministry, researchers from Kyungpook National University discovered the mechanism behind Niemann―Pick Type C disease, an inherited lipid storage disorder that affects the central nervous system.

The symptoms for NP-C ― which is found in 1 in 150,000 people and usually appears in early childhood ― include impaired movement, speech and thought processes, which has led some doctors to refer to it as “childhood Alzheimer’s.”

While recent studies have shown that the amino alcohol sphingosine is a major and initiating compound involved in NP-C, scientists had yet to uncover either the underlying mechanism behind sphingosine storage or its role in NP-C pathogenesis.

Researchers found that sphingosine kinase (SphK) activity is reduced in NP―C patient fibroblasts ― cells that create structural tissue in the body ― due to abnormal levels of a signal protein called vascular endothelial growth factor. The same relationship was found with Purkinje cells, a kind of neuron, in NP―C mice.

By using induced pluripotent stem cells, scientists were able to investigate the cause of the disease and the effects of the signal protein under lab conditions.

The reduction in VEGF levels led to the accumulation of sphingosine in NP-C patients and loss of Purkinje cells in NP-C mice. Researchers also found that accumulation of sphingosine led to the abnormal degradation of cellular components.

They discovered that the abnormalities caused by reduced SphK activity in these cells was resolved by replenishment of the signal protein. This shows that the pathogenic mechanism in NP-C neurons is due to impaired signal protein levels, the researchers said.

“This research pinpointed the spot on which future research on finding a cure (for NP-C) should focus on,” said Jin Hee-kyung, a professor at Kyungpook’s college of veterinary medicine and the corresponding author of the study. Currently, there are no known treatments for NP-C.

The research was published Tuesday in the online edition of the journal Nature Communications.

By Yoon Min-sik (minsikyoon@heraldcorp.com)