autophagy – BioQuakes

Fasting is a key aspect of many religions and diets, yet the question of how healthy it is for one’s body remains a contested one. Intermittent fasting is a trendy new diet, and based on a new study from The University of Wisconsin-Madison, the trend has scientific validity unlike many other popular food trends in the last decade.

Scientists tested different diets on four different groups of mice. One ate a full amount but fasted, one ate as much as they wanted, and two others were underfed. The most healthy mice were the ones who fasted, as they got the right amount of calories, and saw benefits such as longer life, and better blood sugar control.

Why is this? One of the main reasons for this is autophagy, which is the process of moving cell waste. When one is fasting, there is more time in the body for cells to carry out the process. In this process, organelles which have been harmed are removed; they are often brought to the lysosomes. When there is more time to do this, the cell can focus on its normal function more efficiently, while still getting the appropriate calories for function.

Dudley Lamming, head researcher for this study, saw similar results for both male and female mice. He noted that medical research should look at how fasting can be imitated by drugs and treatment as a means of healing, due to its health benefits.

Personally, an aspect of this experiment that I do not love is the mistreatment of animals, being the rats in this case. While there are valid reasons for their use, such as biological similarities to humans, I dislike how some rats are underfed and are harmed. Nonetheless, this is a study that helps prove the benefits of fasting, which can lead to big medical findings in the future regarding human health.

Researchers in Korea have just taken a major step in the journey towards understanding the patterns of our eating behavior. Scientists at the Daegu Gyeongbuk Institute of Science and Technology have recently discovered the dynamics of the enzyme in our brains that controls our appetite.

Previous research has uncovered that the hypothalamus region in our brain detects levels of glucose and hormones in our blood in order to manage our food intake. To extend these findings, the recent research done in Korea has shown that having low amounts of glucose in the bloodstream activates an enzyme, called adenosine monophosphate-activated protein kinase (AMPK). This enzyme alters the properties of neuropeptides, small protein molecules used by neurons to communicate with each other, using autophagy.

Copyright Nevit Dilmen https://en.wikipedia.org/wiki/AMP-activated_protein_kinase#/media/File:MMDB_ID_90115_PDB_ID_3AQV_AMP-activated_protein_kinase.png

Credit Nevit Dilmen

How it Works

When decreased amounts of glucose in the bloodstream are detected, AMPK is stimulated, which diminished the levels of two neurohormones in the brain, neuropeptide Y (NPY) and pro-opiomelanocortin-alpha (POMC). The levels of NPY and POMC are reduced by the process of autophagy, the natural self-destruction mechanism in the body. Decreased amounts of NPY and POMC have been strongly linked to an increase in food intake and obesity.

Research Methods

In orders to trace the complex pathways between the brain and the body to come to these conclusions, researchers conducted experiments using cell lines in vitro and mice. Using the cell lines, researchers were able to record the presence of autophagy under different levels of glucose and activated certain pathways to find the links between the brain and the body. In the mice, researchers injected a virus that eliminated AMPK in the mice’s brains. As a result, the mice ate significantly less than others not injected with the virus.

Combining the results from the cell and mice experiments confirmed that AMPK altered the levels of NPY and POMC, therefore affecting one’s appetite. While these findings are preliminary, they are a significant step in the direction towards completely understanding our eating behavior and may one day lead to solving the obesity epidemic we face today.

More Info:

http://www.healthguidance.org/entry/17442/1/What-Is-AMPk-A-Key-Metabolic-Regulator-Explained.html

https://www.ncbi.nlm.nih.gov/pubmed/17623013

BioQuakes

AP Biology class blog for discussing current research in Biology

Tag: autophagy

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