Naked mole-rats ‘turn into plants’ when deprived of oxygen
By: John Beute ‘20, 4/23/17
Naked mole-rats huddling together underground (Source: Wikimedia Commons)
It is generally known that naked mole-rats have faces that only other naked mole-rats can love. However, if one takes the time to look past their appearance, one can find that these tiny creatures are quite remarkable.
The naked mole-rat lives underground, has an incredibly long life-span for a rodent, hardly ever gets cancer, experiences no pain from the effects of acid, and—as scientists have recently discovered—can survive for long periods of time without oxygen (1, 2).
All known mammals need oxygen to survive. When a mammal is deprived of oxygen, its brain cells can no longer function properly and start to run out of energy. When the oxygen deprivation lasts for too long, the brain cells become overwhelmed and eventually die (1).
But unlike other mammals, the naked mole-rat possesses a unique capability to overcome this obstacle.
According to Thomas Park, a professor of biology at the University of Illinois who has been studying naked mole-rats for close to two decades, the mole-rat has “rearranged some basic building-blocks of metabolism to make it super tolerant to low oxygen conditions (1).”
Park and a team of researchers conducted an experiment in which they deprived naked mole-rats of oxygen using atmospheric chambers. They found that naked mole-rats “tolerated a chronic hypoxic environment of 5% O2 for 5 hours with no apparent ill-effects.” However, under the same conditions, “mice died in less than 15 minutes” (3).
Using a method called gas chromatography-mass spectrometry (GC-MS), Park and his team investigated what differed physiologically between mice and naked mole-rats when each was exposed to oxygen-deficient conditions. They discovered that, under low-oxygen conditions, levels of the simple sugar fructose in the tissues of naked mole-rats increased significantly. No similar change in the concentration of fructose was seen in the tissues of mice under the same conditions (3).
The results of their experiment led Park and his team to conclude that the naked mole-rat has a built-in mechanism that allows its brain cells to burn fructose as an alternative energy source. They do so via a metabolic pathway that was thought to exist only in plants—until now (1).
Under low-oxygen conditions, naked mole-rats send fructose straight to their bloodstreams, where it is then transported to brain cells via molecular fructose pumps. This unique mammalian ability allows the naked mole-rat to stay alive for hours in low-oxygen environments. These same environments would kill a human in minutes. This makes the mole-rat incredibly well-adapted to its underground lifestyle, where oxygen can often be quite scarce (2).
A better understanding of this mechanism could have some incredible implications, including enhanced forms of treatment for patients suffering from oxygen deprivation during crises, such as heart failures and strokes (1).
References:
(1) University of Illinois at Chicago. (2017, April 20). Naked mole-rats ‘turn into plants’ when oxygen is low: Discovery could lead to treatments for heart attack, stroke. ScienceDaily. Retrieved April 23, 2017 from www.sciencedaily.com/releases/2017/04/170420141844.htm
(2) Nelson, B. (21 Apr. 2017). Naked Mole-rats Essentially Turn into Plants When Oxygen Is Low. MNN. Retrieved April 23, 2017 from www.mnn.com/earth-matters/animals/stories/naked-mole-rats-essentially-turn-plants-when-oxygen-low
(3) Thomas J. Park, Jane Reznick, Bethany L. Peterson, Gregory Blass, Damir Omerbašić, Nigel C. Bennett, P. Henning J. L. Kuich, Christin Zasada, Brigitte M. Browe, Wiebke Hamann, Daniel T. Applegate, Michael H. Radke, Tetiana Kosten, Heike Lutermann, Victoria Gavaghan, Ole Eigenbrod, Valérie Bégay, Vince G. Amoroso, Vidya Govind, Richard D. Minshall, Ewan St. J. Smith, John Larson, Michael Gotthardt, Stefan Kempa, Gary R. Lewin. Fructose-driven glycolysis supports anoxia resistance in the naked mole-rat. Science, 2017; 356 (6335): 307 DOI: 10.1126/science.aab3896