Guilt-free sugary treats may be on the horizon as scientists, including one of Indian-origin, have discovered an enzyme that can stop the toxic effects of sugar in various organs of the body. The finding could lead to the development of therapeutics for obesity and type 2 diabetes, researchers said.
The enzyme, named glycerol 3-phosphate phosphatase (G3PP), plays a central role in controlling glucose and fat utilization. Led by Drs Marc Prentki and Murthy Madiraju, the research team at the University of Montreal Hospital Research Centre (CRCHUM) has demonstrated that G3PP is able to detoxify excess sugar from the cells.
"When glucose is abnormally elevated in the body, glucose-derived glycerol-3 phosphate reaches excessive levels in cells, and exaggerated glycerol 3 phosphate metabolism can damage various tissues," said Prentki, a professor at the University of Montreal.
"We found that G3PP is able to breakdown a great proportion of this excess glycerol phosphate to glycerol and divert it outside the cell, thus protecting the insulin producing beta cells of pancreas and various organs from toxic effects of high glucose levels," said Prentki.
Mammalian cells use glucose and fatty acids as the main nutrients. Their utilization inside cells governs many physiological processes such as insulin secretion by beta cells, production of glucose in liver, storage of fat in adipose tissue and breakdown of nutrients for energy production. Derangement of these processes leads to obesity, type 2 diabetes and cardiovascular diseases. The beta cells sense changes in blood glucose levels and produce insulin according to body demand.
Insulin is an important hormone for controlling glucose and fat utilization. However, when beta cells are presented with excess glucose and fatty acids, the same nutrients become toxic and damage them, leading to their dysfunction and diabetes.
When glucose is used in cells, glycerol-3-phosphate is formed, and this molecule is central to metabolism, since it is needed for both energy production and fat formation.
"By diverting glucose as glycerol, G3PP prevents excessive formation and storage of fat and it also lowers excessive production of glucose in liver, a major problem in diabetes," said Madiraju, a scientist at CRCHUM.
"It is extremely rare since the 1960s that a novel enzyme is discovered at the heart of metabolism of nutrients in all mammalian tissues, and likely this enzyme will be incorporated in biochemistry textbooks," Prentki said.
"We identified the enzyme while looking for mechanisms enabling beta cells to get rid of excess glucose as glycerol. This mechanism has also been found to be operating in liver cells, and this enzyme is present in all body tissues," Madiraju added.
The findings were published in the journal PNAS