Susan Bonner-Weir, PhD, Senior Investigator in Islet Cell and Regenerative Biology at Joslin Diabetes Center and Professor of Medicine at Harvard Medical School studies the life cycle of beta cells.
“A beta cell has a life span. It’s born, it’s young, it’s a mature adult, and it becomes aged and senescent, and then it dies,” says Dr. Bonner-Weir. She is working to understand this life cycle to improve treatment and possibly reverse the damage done to beta cells by insulin resistance.
At birth beta cells are immature and don’t respond to changes in glucose. Dr. Bonner-Weir’s previous research pinpointed a hormone produced by the thyroid gland that is the trigger that kick-starts insulin secretion in those immature beta cells. Her work led to a deeper understanding of the process by which insulin-producing beta cells are “born.”
She’s now turning her attention towards the later stages of a beta cell’s life. “We’re focused now on what happens with aged beta cells even in a young pancreas and what we found…is that it’s a little bit dysfunctional and can’t put out as much insulin,” she says.
“We also found that insulin resistance…or various [other] stresses can accelerate the aging of the beta cell.” She is studying whether or not that accelerated aging process can be reversed if caught in time.
Initial experiments show promising results. “With a week of acute insulin resistance you can recover,” she says. “Now we’re doing experiments [that ask] what if you had [insulin resistance for] two weeks, four weeks—how long does it take for insulin resistance to really drive a cell so that it becomes aged and senescent and cannot be rejuvenated?”
She hopes that by understanding the length of the window of opportunity to reverse the aging, people with type 2 diabetes could have an opportunity to heal their own beta cell supply.