Sleep deprivation affects stem cells in cornea

Sleep deprivation is a serious health problem and it has negative impacts on mental and physical health. Eye problems such as dryness and itching are commonly experienced after episodes of sleep deprivation, while long-term sleep deprivation comes with an increased risk for eye disease.

The cornea, which is the transparent tissue layer covering the eye is essential for assuring the health and function of the eye. The cornea is maintained by stem cells, which divide to replace dying cells and repair small injuries. Corneal stem cell activity needs to be precisely tuned to assure an adequate output of new corneal cells, and dysregulation of corneal stem cells can lead to eye disease and impaired vision.

In a study recently published in Stem Cell Reports, researchers Wei Li, Zugou Liu and colleagues from Xiamen University, China, and Harvard Medical School, USA, evaluated how sleep deprivation impacts corneal stem cells. Their experiments in mice showed that short-term sleep deprivation increased the rate at which stem cells in the cornea multiplied.

At the same time, sleep deprivation altered the composition of the protective tear film, reducing the tear film antioxidants in sleep-deprived mice. The researchers found that the tear film composition had a direct impact on corneal stem cell activity and, encouragingly, the application of teardrops containing antioxidants reversed the excessive stem cell activity.

The study revealed that serious effects on corneal health, such as thinning and ruffling of the cornea and loss of transparency, were seen after long-term sleep deprivation. Further, corneas of long-term sleep-deprived mice contained fewer stem cells, suggesting that persistent stimulation of stem cell activity over longer periods led to exhaustion and loss of corneal stem cells.

These data suggest that sleep deprivation negatively affects the stem cells in the cornea, possibly leading to vision impairment in the long run. Further studies are required to confirm that similar processes are happening in human corneal stem cells and in patients, and to test if local antioxidant therapy may overcome some of the negative effects of sleep deprivation on corneal health.