Researchers at Karolinska Institutet and KTH Royal Institute of Technology have developed an improved method for creating insulin-producing cells from human stem cells. In a newly published study, the team demonstrated that these cells effectively regulate blood sugar levels in laboratory tests and can reverse diabetes in mice.
“We have developed a method that reliably produces high-quality insulin-producing cells from multiple human stem cell lines,” said Per-Olof Berggren, PhD, professor at the Department of Molecular Medicine and Surgery, Karolinska Institutet. “This opens up opportunities for future patient-specific cell therapies, which could reduce immune rejection.” Berggren and Siqin Wu, PhD, researcher at Spiber Technologies AB (formerly at Karolinska Institutet), are co-corresponding authors of the researchers’ published paper in Stem Cell Reports, titled “An optimized protocol for efficient derivation of pancreatic islets from multiple human pluripotent stem cell lines.”
Type 1 diabetes (T1D) occurs when the immune system destroys insulin-producing cells in the pancreas, meaning the body can no longer absorb glucose from the blood and regulate blood sugar levels. “In type 1 diabetes (T1D), autoimmune destruction of β cells results in loss of glycemic control,” the authors wrote.
One possible treatment strategy is to replace these cells with new ones. However, previous methods of producing such cells from stem cells have often yielded mixed results. Stem cell therapy for type 1 diabetes is already being tested in several clinical trials. However, a challenge with previous methods is that the stem cells often develop into a combination of the desired and undesired cell types, increasing the risk of complications. Another challenge is that the insulin-producing cells created are often not mature enough to respond well to glucose.
“The success of cell therapy for type 1 diabetes (T1D) depends on reliable differentiation of stem cells into functional pancreatic islets,” the authors noted. They pointed out that previous protocols have exhibited variable efficiency across different human pluripotent stem cell (hPSC) lines. “Differentiation beyond the stage (S) 4 pancreatic progenitor (PP) stage frequently yields heterogeneous cultures containing proliferative non-endocrine cells and immature endocrine cells … increasing the risk of cyst or tumor formation,” the team further commented.
The newly optimized production process reported by Berggren and colleagues yields more mature and purer insulin-producing cells than previous methods. In a laboratory setting, the cells were able to secrete insulin and responded strongly to glucose. When the researchers transplanted these cells into streptozotocin (STZ)-induced diabetic mice, the animals gradually regained the ability to regulate their blood sugar. “By adjusting the culture steps and allowing the cells to form three-dimensional clusters themselves, many unwanted cell types are eliminated and the cells gain a better ability to respond to glucose, according to the researchers. “Single-cell analyses show that the SC-islets are free of non-endocrine cell populations before and after transplantation,” the team stated.
The transplantation was performed in the anterior chamber of the eye (ACE) which provides a transparent and accessible site for noninvasive monitoring of engrafted SC-islets through the cornea, the team pointed out. Transplantation into this compartment is also straightforward and minimally invasive. In their paper, the team noted, “Intraperitoneal glucose tolerance tests (IPGTT) at three, four, and six months post-transplantation showed improved glucose handling over time … SC-islet transplantation reversed hyperglycemia by three months, and by five–six months blood glucose levels fell slightly below pre-STZ baselines.”
Berggren commented, “This is a technique we use to monitor the development and function of the cells over time in a minimally invasive way. We observed that the cells gradually matured after transplantation, retaining their ability to regulate blood sugar for several months, which demonstrates their potential for future treatments.”
Fredrik Lanner, PhD, professor at the Department of Clinical Science, Intervention and Technology, Karolinska Institutet, and last author of the paper, added, “This could solve several of the problems that have previously hindered the development of stem cell-based treatments for type 1 diabetes. Building on this, we will work towards clinical translation aiming at treating type 1 diabetes.” In their report the authors concluded, “Our protocol generated glucose-responsive SC-islets from all eight hPSC lines tested … demonstrating potential for autologous applications … Our efficient differentiation protocol represents a key step toward autologous cell therapy, though further work is required to realize this goal.”
