This is the story of how two people could save millions of lives as their genes have revealed a treatment for diabetes, one of the top 10 causes of death in the world. The two people in question have neonatal progeroid syndrome (NPS), a rare disorder characterised by very low levels of body fat, short stature and aged appearance. Analysis of their DNA has revealed a new hormone which the researchers have named Asprosin, after the Greek word for white as people with NPS have reduced levels of white adipose tissue, which is where the hormone is secreted from.
Asprosin binds to receptors on liver cells causing a signaling cascade which ends in the release of glucose – this boosts blood sugar levels between meals. The cascade is then switched off by a negative-feedback loop when glucose levels rise. People with NPS lack the Asprosin hormone, so often feel lethargic as their blood sugar levels drop drastically even after a meal. It also works in the opposite direction – people with obesity or diabetes have high blood glucose and insulin levels and high Asprosin levels.
The researchers were quick to realize the implications of Asprosin in diabetes treatment and so it wasn’t long before the beloved model organism, the mouse, got the Asprosin treatment. First, mice were exposed to increased levels of Asprosin by injection or by inserting extra copies of the gene into their liver. This resulted in elevated glucose and insulin levels between meals, mimicking the effects of diabetes. Consequently, when they blocked Asprosin using an antibody in mice with insulin resistance, the mice showed a reduction in insulin levels whilst maintaining normal blood sugar levels. This suggests that if patients with diabetes are treated with antibodies to block Asprosin signalling this would reduce the number of times they have to inject insulin, or they may even stop taking it.
Spurred on by these findings, the researchers are carrying out more tests on mice using antibodies that block Asprosin and hope to carry out a trial in humans within a couple of years. Following on from this, they want to start looking at how Asprosin is linked to obesity and whether there is the potential for another treatment.
Kate Dearling
