Sleep Deprivation Linked To Diabetes, Age

shutterstock_123691804Sleep has long been known to have an effect in different parts of the body. It is the natural way that the body recharges or takes a rest. While it plays an important role in human health, researchers have not yet fully understood the effects that sleep deprivation may have on the molecular level. While lack of sleep may prove to be detrimental, many researchers do not really have a good idea just what processes go through that leads to that result.

Researchers from the Perelman School of Medicine at the University of Pennsylvania have studied the effects of sleep. Initial studies indicated that sleep deprivation could cause cells to affect the UPR or the unfolded protein response, a process where misfolded proteins may get degraded or refolded. The researchers have showed in a study five years ago that UPR is an adaptive response to stress brought about by sleep deprivation. This process is also impaired in the brains of old mice. This suggests that inadequate sleep among the elderly, who normally already experience sleep disturbances can even worsen an already impaired protective response to proteins misfolding that happen on aging cells. A recent follow-up study shows how sleep deprivation may affect the UPR on the pancreas.

According to Nirinjini Naidoo, Ph.D., a senior author in the follow-up study, stress in the pancreatic cells as a result of sleep deprivation may play a significant role in the loss or dysfunction of these cells, which are important in the proper maintenance of blood sugar levels. Moreover, these functions may also get worse in normal aging.

“The combined effect of aging and sleep deprivation resulted in a loss of control of blood sugar reminiscent of pre-diabetes in mice. We hypothesize that older humans might be especially susceptible to the effects of sleep deprivation on the disruption of glucose homeostasis via cell stress,” Naidoo added.

Naidoo and other Penn researchers wanted to know whether sleep deprivation causes stress in a cell compartment called endoplasmic reticulum or ER of the pancreas, where some of the proteins are made and where the UPR functions as a quality control system. Naidoo believes that this will lead to an increase in protein misfolding. The team started examining the tissues in mice for evidence of cellular stress as a result of acute sleep deprivation. The results show that both age and sleep deprivation combine to induce cellular stress in the pancreas of the mice.

Upon further examination, the team saw that the older mice had it worse when they were subjected to sleep deprivation. Pancreas tissue from both older and younger mice exhibited increased signs of misfolding protein yet both were able to maintain insulin secretion and control their blood sugar levels. Aged mice that went through acute sleep deprivation showed a marked increase in CHOP, a protein associated with cell death. This indicates that there is a maladaptive response to cellular stress with aging that can be amplified by sleep deprivation.

Source: Perelman School of Medicine at the University of Pennsylvania. “Sleep-deprived mice show connection with diabetes, age.” ScienceDaily, 11 Dec. 2013. Web. 19 Dec. 2013.

 

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