Can GLP-1 agonists regenerate cells in the pancreas?
GLP-1 agonists regenerate beta cells in rodents, but whether this also occurs in humans has not yet been demonstrated. Until clinical evidence is available, this effect cannot be counted on as a treatment goal.
In rodents with diabetes, GLP-1 agonists stimulate the formation and proliferation of beta cells in the pancreas. They also protect those cells from dying. In addition, new beta cells are formed from precursor cells in the pancreatic ducts. This has been demonstrated in multiple animal models and also applies to a related class of drugs (DPP-4 inhibitors).
In humans, this works differently. GLP-1 agonists as monotherapy do not manage to measurably increase the division of human beta cells. They do stimulate insulin secretion and suppress appetite, but regeneration of beta cells in living humans has not been demonstrated. Whether the formation of new beta cells from precursor cells, as seen in animals, is also active in humans is unknown.
There are, however, preliminary indications from laboratory and mouse research that a combination of a GLP-1 agonist with an experimental agent that inhibits a growth-blocking factor (DYRK1A) has a greater effect. In those experiments, beta cell proliferation rose from approximately 2% to 5 to 6%, without the cells losing their identity. This is interesting, but this combination is experimental, not approved, and the mouse experiments lasted only one week.
GLP-1 agonists protect beta cells against programmed cell death. This has also been observed in isolated human islets in the laboratory. But whether that protective effect translates into less beta cell loss in living patients with diabetes is a question that the review authors explicitly leave open. Clinical evidence for a measurable change in beta cell mass in humans is lacking.
This answer is based on several review articles on GLP-1 biology and one non-indexed study on the combination treatment with a DYRK1A inhibitor. The findings from animal research are broadly described and consistent, but direct human clinical data are entirely absent. The review authors themselves emphasise that the question of whether GLP-1 therapy changes beta cell mass in humans remains unanswered. The evidence for the combination treatment comes from short-term laboratory and mouse research and is therefore thin.