Two substances that occur naturally in the brain act to protect the brain during a stroke. This is the conclusion of a dissertation published at the Sahlgrenska Academy, and the discovery may lead to new treatments for stroke patients.
Stroke is the result of an infarction, or bleeding, within the brain, and it may lead to impaired movement, impaired sensation, and difficulties in cognitive function and speech. Approximately 30,000 people are affected by stroke each year in Sweden, and it is the most common cause of long-term dependence on care.
"Researchers all over the world are intensively searching for new treatments. One interesting possibility is that of activating stem cells in the damaged brain such that the brain can be repaired and regain its function", says stem cell researcher Jonas Faijerson.
Stem cells are immature cells that reside in selected regions of the adult brain. These cells can develop either into nerve cells or into other cells that are important in the brain, such as astrocytes. Astrocytes are the most abundant cell type in the brain, and they play an important role when the brain is damaged.
The dissertation shows that activated astrocytes release substances that activate stem cells within the brain.
"We have shown that a very interesting hormone known as 'TRH' is released in large amounts after a stroke, and that this hormone can not only protect from damage but also lead to the activation of stem cells", says Jonas Faijerson.
The stem cells also release survival factors to the surrounding brain tissue when the brain is injured or diseased. The dissertation describes the identification of a completely unknown survival factor, which the researchers have named "pentinin".