A new study found a secret gene deep in our kidneys that aids with stress removal from cells.
Scientists at the joint neurobiology lab at the Weizmann Institute of Science with the Max Planck Institute of Psychiatry in Germany mapped out gene sequences for cells traveling from the brain, when stress is activated, down to the adrenal glands in the kidneys, to track how and where stress develops, to get a better idea of how to treat stress-related health problems.
The study was published in the peer-reviewed journal Science Advances.
So how does stress work?
It begins in the brain, in the hypothalamus, the almond-shaped collection of nuclei in the middle of our heads responsible for steering the actions of the nervous and endocrine system. As such, it moves from there, through the pituitary gland right next to the brain, along what's called the “stress axis,” and ends up at the adrenal glands down in the kidneys, which produce the hormone cortisol.
On a non-consistent basis, this process can manifest itself in clenched stomachs or jaws. In the long term, however, it can result in anxiety, depression, severe psychological disorders, as well as mess with the body's metabolism, hasten aging, and even lead to diabetes.
What Prof. Alon Chen and Dr. Juan Pablo Lopez did in Chen's lab at the Weizmann Institute of Science is “map out” the entirety of the stress axis, tracking the activity of cells as they pass from the brain to the adrenal glands.
They found that as the cells moved from one organ to the next along the axis their structure and tissue were visibly and increasingly changed. The cells were studied at three different points.
Meaning, the physical makeup of the genes themselves changed, increasing in number as they worked down the axis.
The scientists found this by analyzing the cells along the stress axis of two groups of mice. The first was not exposed to any stress, while the second was chronically stressed.
Early on, in the hypothalamus, 66 genes were changed from the unstressed group of mice to the stressed. That number increased to 692 in the pituitary glands, and culminated at 922 in the adrenals.
That is a significant number of altered genes - of altered cells - especially in the adrenal glands, which the study noted can visibly change their size under continuous cortisol exposure.
But what in the adrenal glands is responsible for the burst of changed cells? What the scientists discovered, through this unprecedented examination method, is that it is a group of endocrine cells situated in the outer layer of the glands.
A specific gene had “over expressed” itself in the cells in the stressed group of mice. Known as ABCB1, it removes specific substances from the cell, which the research team believes is somehow connected to the release of cortisol.
How? “If extra stress hormones are created, the cell needs extra release valves to let those hormones go,” explained Lopez.
If this was only tested on mice, how does it apply to humans? People suffering from Cushing's disease — an excess of cortisol production in the pituitary gland thanks to a tumor which raises the levels of the stress hormone in the blood — had their adrenal glands removed to lower the stress hormone levels. When the glands were studied, they looked similar to the those of the chronically-stressed mice.
ABCB1, in its other forms, has been identified with a high risk of depression, in the way it similarly reacts to both stress and depression.
“Most research in this field has focused on chronic stress patterns in the brain,” said Chen. “In addition to presenting a possible new target for treating the diseases that arise from chronic stress, the findings of this study will open new directions for future research.”
