Kristal Wong —
Who doesn’t want to be beautiful? Who doesn’t want straight A’s? According to scientists at the University of Manchester in the UK and Duke-NUS Medical school in Singapore, experts believe that sleeping may help you to achieve both beauty and brains1,2,3. The key is the body’s circadian rhythm and body clock mechanism. The scientists in Manchester, led by Dr. Chang, compared normal mice to genetically engineered mice with a mutation that blocked the mouse’s internal clock mechanism. Through repeated screenings with electron microscopy, the proteomics of collagen in murine extracellular matrix (ECM) were tracked throughout the day, ultimately demonstrating that sleep is essential for tissue repair and maintaining homeostasis2.
The ECM makes up roughly half of the human body. Most of the ECM is comprised of collagen, a fibrous ropelike protein. Collagen regulates tissue shape and structure and is therefore an essential determinant of physical beauty. It was long believed that collagen was generated in the cell until the age of 17 and left unregulated thereafter2. However, collagen is exposed to tissue wear and tear daily. Thus, it is reasonable to believe that collagen needs a homeostatic regulatory mechanism to repair or protect its aging, worn, and damaged fibers.
Dr. Chang’s team have uncovered and differentiated the functions of two types of collagen: thick and thin fibers. Thick fibers were found to be unchanged throughout the study, presumably in part due to their high elasticity. Interestingly, the concentration of thin fibers was found to cycle throughout the day. This pattern of protein production suggests a process of collagen deterioration during the day (perhaps at stressful moments) and regeneration during sleep. In the mutated mice (lacking adequate circadian clock mechanisms), microscopy uncovered irregular fiber structures. The thick fibers displayed a bulkier appearance than they did in normal mice and exhibited reduced elasticity and strength. Additionally, Chang discovered normal murine tissue comprised of thin collagen fibers woven between thick fibers. This close arrangement of the fibers suggests that the frequent contact between these fibrous surfaces and the generation of a sheer-stress loading mechanism also play an important role in the homeostatic regulation of collagen and tissue. Furthermore, for the mice with the internal clock mutation, it is likely that their impaired sleep regulation hindered the repair of collagen2.
On a related note, researchers led by Dr. Lo at the Duke-NUS Medical School in Singapore found that a lack of sleep could result in irreversible cognitive deficits over that time period. In a study of high-achieving university students, Lo and her team found that partial sleep deficits over a week, 5 hours vs. 9 hours, lead to weakened cognitive function, alertness, and performance, unable to be salvaged with two nights of regular sleep3.
In summation, the benefits of sleep include both tissue collagen repair and proper neurobehavioral functioning. And as young college students, it is essential that we prioritize sleep for both our bodies, and our brains.
- Beauty sleep could be real, say body clock biologists. (2020, January 15). ScienceDaily. Retrieved from https://www.sciencedaily.com/releases/2020/01/200115120626.htm
- Chang, J., Garva, R., Pickard, A., Yeung, C.-Y. C., Mallikarjun, V., Swift, J., Kadler, K. E. (2018). Circadian control of the secretory pathway is a central mechanism in tissue homeostasis. BioRxiv (Preprint). doi: 10.1101/304014
- Lo, J. C., Ong, J. L., Leong, R. L., Gooley, J. J., & Chee, M. W. (2016). Cognitive Performance, Sleepiness, and Mood in Partially Sleep Deprived Adolescents: The Need for Sleep Study. Sleep, 39(3), 687–698. doi: 10.5665/sleep.5552