Dr. Camper Connects with Multiple Cores to Explore Islet 1’s Surprising Role in Pituitary Development

Sally Camper, Ph.D.

Sally Camper, Ph.D. is the Margery Shaw Distinguished University Professor of Human Genetics and Internal Medicine at the University of Michigan Medical School. Her research on pituitary gland dysfunction has revealed important information on the source of birth defects through an unexpected discovery.

Dr. Camper’s research focused on the Islet 1 gene, known for being very important to the development of the heart, pancreas, and vision, but with an unknown role in the pituitary gland. The pituitary gland plays a significant role in human physiology. Referred to as the “master gland,” it regulates many bodily functions including: fertility, growth, metabolism, and the stress response. The organ doesn’t develop properly in some children with birth defects, resulting in pituitary disorders.

The Medical School’s Transgenic Core was used to create a tool that could specifically delete genes in the pituitary gland if those cells were expressly engineered a certain way. The tool is very significant to Dr. Camper’s research on pituitary dysfunction as it is the very first of its kind. It was used to remove the Islet 1 gene from the pituitaries of laboratory mice.

Dr. Camper said she anticipated that the removal of Islet 1 would cause failure of the pituitary to develop hormone-producing cells. What happened instead surprised researchers. Some normal cells developed, but there were numerous fluid-filled cysts called Rathke cleft cysts. This was not the answer they were looking for, but the new discovery confirmed just how important Islet 1 is to pituitary development, much more than was previously known.

Cysts have ciliated cells, express keratin 8 (Image provided by Sally Camper)

Rathke cleft cysts are a birth defect. They are rare and not cancerous but can be problematic causing symptoms such as visual disturbance and headaches. As the cysts grow, they can put pressure on the pituitary gland and they can also put pressure on optic nerves located above the pituitary gland. Other symptoms include nausea, fatigue, and diabetes insipidus. They’re classified as an embryologic abnormality because they develop during growth in the womb. Current treatment for pituitary cysts includes surgery to drain the cyst or remove it if symptoms persist. If symptoms are not problematic, the cysts can be left alone.

The goal for Dr. Camper’s research going forward is to see if tissue being studied in mice is similar to or matches tissue removed from humans who have had Rathke cleft cysts removed. Dr. Camper plans to collaborate with researchers in Iowa and the UK to view the human tissue samples and compare them to tissue found in mice. She also hopes to discover more information on what causes Rathke cleft cysts to occur and learn more about how they develop.

Though Dr. Camper and her lab have made exciting progress, the discovery doesn’t point directly to a cure for these birth defects. Researchers are still trying to figure out what can prohibit these cysts from growing in the first place. Preventative treatment could be many years away, but now that an animal model exists, researchers can work to discover what might inhibit these cysts from growing and possibly transition it into a therapy in the future.

Dr. Camper’s discovery would not have been possible without Michelle Brinkmeier, the lead staff member on this project, and the Transgenic Core. The Transgenic Core was instrumental in creating the very first animal model of the Rathke cleft pituitary cysts disorder. Dr. Camper also tapped the Advanced Genomics Core to do an RNA Sequencing experiment on pituitary tissues from mice with and without Islet 1. This experiment showed all of the gene expression differences and revealed genes that might drive cyst formation. Once the sequencing was complete, the Bioinformatics Core analyzed the RNA Sequencing data.

Sally has worked at U-M for 29 years. Upon arriving at the University, she founded the Transgenic Core in 1989, spending two decades leading the Core. She also spent 11 years as the Human Genetics department chair. Her current focus is on her research.