A team headed by Harvard Medical School scientists has taken steps to unravel a dementia that surfaces early in a person’s life. The study, published in Neuroscience News and Nature Communications in October 2022, describes their discovery of a genetic type of frontotemporal dementia (FTD).
This variant of frontotemporal dementia was linked to an accumulation of certain lipids found in the brain resulting from a deficiency of a protein that disrupts cell metabolism.
About the Types of Dementia
The term ‘dementia’ describes a group of symptoms affecting fifty-five million people in the world, yet there are few effective treatments.
The four types of dementia are: frontotemporal dementia, Alzheimer’s disease, Lewy body dementia, and vascular dementia.
Each type of dementia has complicated genetics with its own mutations. For example, FTD is characterized by the loss of cells in the brain’s temporal and frontal lobes, accounting for between five to ten percent of all dementia cases. FTD is mostly found in people forty-five to sixty-five years of age.
The Cleanup Crews
FTD is associated with a GNR gene mutation in fifteen percent of cases. When a person has FTD, the brain cells no longer make the protein progranulin.
The cell ‘cleanup’ or general metabolic activities is the responsibility of lysosomes. They have earned the nickname ‘Cleanup Crews’ because they break down cell waste material.
Initially, the researchers discovered an accumulation of gangliosides in human cells and specifically in the brain cells of FTD patients. Gangliosides are lipids that are found in the body’s nervous system.
Using newly developed technology, the researchers identified lysosomes in the brains of FTD patients with reduced amounts of progranulin and below-normal levels of BMP lipid. BMP breaks down gangliosides.
Adding BMP
The team found when they added BMP to cells there was a much lower accumulation of gangliosides in the brain cells. This is an indication that a buildup of gangliosides may play a role in the development of FTD.
Senior co-author Robert Farese Jr. Professor of molecular metabolism at Harvard’s Chan School announced that the team uncovered progranulin’s role in the degradation of gangliosides as well as the potential to correct the problem.
Professor Harper commented that the lysosome could be the key to various neurodegenerative diseases, although in all probability they connect in different ways.
