Carlos Solis
A new study found a surprising trick the body uses to control blood sugar: in low-oxygen environments, red blood cells soak up extra glucose and convert it into a molecule that helps hemoglobin release oxygen to tissues.
“This work highlights an important role for red blood cells in diabetes regulation,” said lead author Isha Jain of the Gladstone Institutes and the University of California, San Francisco. “We may be able to target this idea pharmacologically in the future.”
Red blood cells become glucose sponges
Scientists exposed mice to air with 8 percent oxygen to mimic high-altitude conditions, while a control group breathed normal air with 21 percent oxygen. After several weeks, researchers gave all the animals a glucose injection and measured their blood-sugar levels.
Mice living in low-oxygen conditions showed much smaller blood sugar spikes; they cleared glucose from their blood faster. The effect persisted for several weeks even after the animals returned to normal air, which points to lasting metabolic changes following hypoxia.
But scans couldn’t fully account for the missing glucose: the liver, muscles, and other large organs did not explain the full amount consumed. That gap led the authors to suspect that the circulating blood cells themselves were taking up the sugar.
Further analysis showed that red blood cells produced under hypoxia had higher levels of the GLUT1 protein, which sits in the cell membrane and helps glucose enter the cell. These cells had about twice as much GLUT1 and three times the glucose uptake of normal red blood cells. Labeling existing red blood cells before the low-oxygen exposure confirmed that these adaptations appeared only in new cells made during hypoxia.
Implications for treating diabetes
The authors say the findings open new avenues for diabetes treatment. In the lab, researchers gave mice an experimental compound called HypoxyStat. The drug increases hemoglobin’s affinity for oxygen, so it holds onto oxygen longer and mimics hypoxia. The idea is that a pill that simulates oxygen deprivation could boost production of glucose-absorbing red blood cells.
Researchers caution that much more work is needed before testing such drugs in people. Transfusing red blood cells would not be a practical diabetes treatment by itself, but the results suggest other possibilities, such as engineering red blood cells that absorb glucose more effectively.
Based on reporting from Live Science
