Diabetes reverted in mice with CRISPR–Cas9 gene-edited cells from patients
iPSCs from a patient with Wolfram syndrome were programmed into insulin-producing cells, which alleviated diabetes when transplanted into mice.
A research team from Washington University School of Medicine (MO, USA) transformed skin cell-derived induced pluripotent stem cells (iPSCs), from a patient with Wolfram syndrome, into insulin-producing cells. CRISPR–Cas9 gene editing was used to correct the mutation causing Wolfram syndrome in the human stem cells. The edited cells were then implanted into laboratory mice and found to reverse diabetes. The findings, published in Science Translational Medicine, may hold promise as a treatment for diabetes.
"This is the first time CRISPR has been used to fix a patient's diabetes-causing genetic defect and successfully reverse diabetes," explained Jeffrey R. Millman (Washington University). "For this study, we used cells from a patient with Wolfram syndrome because, conceptually, we knew it would be easier to correct a defect caused by a single gene, but we see this as a steppingstone toward applying gene therapy to a broader population of patients with diabetes."
In this study, the research team derived beta cells from patients with Wolfram syndrome and used CRISPR–Cas9 gene-editing to edit a mutation in WFS1, the gene that causes Wolfram syndrome. The gene-edited cells were then compared to insulin-secreting beta cells from the same batch of iPSCs that had not been edited with CRISPR.
It was found that beta cells that were edited with CRISPR more efficiently secreted insulin in response to glucose, both in the test tube and in mice with a severe form of diabetes. Signs of diabetes disappeared in the mice that received the CRISPR-edited cells, implanted beneath the skin, with the blood sugar levels remaining within a normal range for the six-month period they were monitored. In contrast, mice that received unedited beta cells remained diabetic.
"We basically were able to use these cells to cure the problem, making normal beta cells by correcting this mutation," stated Fumihiko Urano (Washington University). "It's a proof of concept demonstrating that correcting gene defects that cause or contribute to diabetes – in this case, in the Wolfram syndrome gene – we can make beta cells that more effectively control blood sugar. It's also possible that by correcting the genetic defects in these cells, we may correct other problems Wolfram syndrome patients experience, such as visual impairment and neurodegeneration."
The research team hope to use CRISPR in the future to correct mutations in beta cells of patients whose diabetes is a result of genetic and environmental factors.
"We're excited about the fact that we were able to combine these two technologies – growing beta cells from induced pluripotent stem cells and using CRISPR to correct genetic defects," continued Millman. "In fact, we found that corrected beta cells were indistinguishable from beta cells made from the stem cells of healthy people without diabetes."
The scientists are now working on less intrusive methods for making pluripotent stem cells from blood and are currently developing a method using urine samples.
"In the future," Urano concluded, "we may be able to take a few milliliters of urine from a patient, make stem cells that we then can grow into beta cells, correct mutations in those cells with CRISPR, transplant them back into the patient, and cure their diabetes in our clinic. Genetic testing in patients with diabetes will guide us to identify genes that should be corrected, which will lead to a personalized regenerative gene therapy."
Sources: Maxwell K, Augsornworawat P, Velazco-Cruz L et al. Gene-edited human stem cell-derived ß cells from a patient with monogenic diabetes reverse pre-existing diabetes in mice. Sci. Transl. Med. 12(540), eaax9106 (2020); https://medicine.wustl.edu/?p=86570&preview=1&_ppp=3fb74e7d45