By introducing a protein called cdk6 into human insulin-producing adult beta cells via a virus, University of Pittsburgh School of Medicine researchers have induced the cells to replicate “robustly.” Previously, scientists believed that beta cells could be induced to regenerate slowly at best, and usually not at all.
The Pittsburgh researchers found that, unlike beta cells found in laboratory mice, human beta cells contain significant amounts of cdk6, a protein that causes the cells to regenerate and replicate. To make the human beta cells increase cdk6 production, they used a virus to introduce the gene for the protein into the cells. Cells untreated with the gene did not replicate.
The researchers placed the now replicating cells under the outer layers of kidneys in diabetic mice. The cells thrived, and the insulin they produced eventually normalized the rodents’ blood sugar levels-in essence curing their diabetes. When the cells were removed, the mice reverted to their diabetic state.
This research is yet another example of how scientists are learning to “piggy-back” genes or hormones onto other molecular compounds to introduce them into the body or to slip them past the body’s immune defenses. It opens the way for further studies that could lead to ways to dramatically increase replication of beta cells from cadavers or patients’ own stem cells, or even to the creation of drugs that could “tell” beta cells to ramp up their insulin production.