"We were expecting the results to last 48 to 72 hours, not several months.”
Researchers at Salk University’s Gene Expression Laboratory investigated how a protein injection would affect mice with type 2 diabetes, and they were shocked at what they observed.
The growth-promoting hormone, Fibroblast Growth Factor 1 (FGF1), is known to lower blood-glucose levels in diabetic mice, and it had previously been shown to bring about healthy blood sugar levels in diabetic mice for up to two days after injection.
However, the researchers tweaked the experiment by injecting the protein directly into the animals’ brains, and the effect was dramatically extended. The researchers expected the protein to have an impact for a couple days, but healthy blood sugar levels were restored in mice for up to 17 weeks — the researchers call it a “sustained remission.”
Of course, since the study was done on mice, there’s no saying whether these effects would translate into humans, nor are the researchers implying that they’ve found a cure.
Nonetheless, it’s a leap forward with FGF1 research, and the findings could lead researchers to a new potential target for diabetic treatments — the brain. Most diabetic treatments focus on organs and organ systems in the body, but perhaps the brain holds the answer we’ve been looking for.
"We think that diabetes represents a dysfunction of neural circuits within the brain,” the study’s lead researcher Jarrad Scarlett told EndocrineWeb. “What FGF1 is doing is acting upon these circuits to ameliorate the dysfunction.”
"We were expecting the results to last 48 to 72 hours, not several months," Scarlett continued. "We think it's stimulating synaptic remodelling within these circuits."
According to the study results, which have been reported in the journal Nature Medicine, after the initial peptide injection, the researchers saw an increase in the brain’s production of neuroprotective proteins, as well as strengthened connections in the hypothalamus — a brain region involved in regulating appetite and metabolism.
The team repeated the experiment on two more sets of rodents to confirm these results, administering an injection to rats and to a second group of mice. Again, they saw that the protein led the animals into sustained remission.
Plus, it doesn’t hurt that the injection had no side effects.
“With FGF1, we really haven’t seen hypoglycemia or other common side effects,” Salk postdoctoral research fellow Jae Myoung Suh, first author of the paper, said in a press release. “It may be that FGF1 leads to a more ‘normal’ type of response compared to other drugs because it metabolizes quickly in the body and targets certain cell types.”
Unfortunately, human treatments inspired by these findings would still be several years away. But there is a silver lining — the researchers say that humans wouldn’t have to endure injections to the head in order to reap the benefits of the protein-therapy. Instead, some type of nasal ingestion could do the job.
“We want to move this to people by developing a new generation of FGF1 variants that solely affect glucose and not cell growth,” Ronald M. Evans, director of Salk’s Gene Expression Laboratory and corresponding author of the paper, said in the release. “If we can find the perfect variation, I think we will have on our hands a very new, very effective tool for glucose control.”
For more information, see the Salk Institute’s video below.
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