Scientists have found a way to efficiently engineer new thyroid cells from stem cells. The discovery, performed in mice, is the first step toward engineering new human thyroid cells in order to better study and treat thyroid diseases.
A report on the work - led by Boston University School of Medicine (BUSM) in Massachusetts - is published in the journal Stem Cell Reports.
The thyroid is a gland in the middle of the lower neck. Although only small, it produces hormones that reach every cell, organ, and tissue to help control metabolism - the rate at which the body makes energy from nutrients and oxygen.
It is thought that around 20 million people in the United States are living with some form of thyroid disease, the causes of which are largely unknown.
Most thyroid disorders are chronic or life-long conditions that can be managed with medical attention. However, approximately 60 percent of cases are undiagnosed.
Toward mass production of human thyroid cells
Stem cells are cells that have the potential to mature into many different cell types. Particular patterns of genetic switches and signals direct the maturing stem cells toward their individual fates.
- Hyperthyroidism has several causes and is more common in women than men
- Symptoms include: disturbed sleep, nervousness, muscle weakness, irritability, vision problems, and unexplained weight loss
- Graves' disease is a type of hyperthyroidism that affects around 1 percent of the population.
In their study, the researchers found a way to coax genetically modified embryonic stem cells from mice to develop into thyroid cells.
They discovered that there is a "window of opportunity" for doing this efficiently that occurs during cell development.
As they guided the laboratory-cultured embryonic stem cells through various stages of development, the researchers switched a gene called Nkx2-1 on and off for short periods.
They discovered a small timeframe during which the Nkx2-1 gene is switched on that converts the majority of the stem cells into thyroid cells.
Researchers believe that the discovery is the first step toward an effective human stem cell protocol for creating research models and new treatments for thyroid diseases. The principle may also apply to other cell types, they add.
In their paper, they note that stem cells hold great promise as a way to mass produce differentiated cells for research. However, a major roadblock to achieving high yields has been "the poor or variable differentiation efficiency of many differentiation protocols."
"This method resulted in high yield of our target cell type, thyroid cells, but it may be applicable for the derivation of other clinically relevant cell types such as lung cells, insulin-producing cells, liver cells, etc."
Senior author Prof. Laertis Ikonomou, BUSM