For a group of mice in Dr. Andrew Campbell’s lab, the pain caused by sickle cell anemia just started to go away.
Campbell, a pediatrician and director of the Pediatric Comprehensive Sickle Cell Program at the University’s Cancer Center, is the lead author of a study published last month that is the first to use specific proteins in the human body to prevent sickle cell disease.
Sickle cell anemia is a hereditary disease of the blood, which causes red bloods cells to form in an abnormal crescent moon shape, instead of the normal disk shape. These sickle-shaped cells are more fragile than normal red blood cells and deliver less oxygen to tissues in the body. Deprivation of oxygen to tissues can often cause organ damage and lead to death.
According to the Centers for Disease Control and Prevention, 90,000 to 100,000 Americans have sickle cell anemia. The disease, which is identified by a lower than normal fetal hemoglobin count, is prevalent in Africa and found in about one out of 500 African-American babies born.
In the study, Campbell successfully increased fetal hemoglobin levels in mice with sickle cells. Increasing the production of TR2 and TR4 proteins has the potential to prevent and reduce organ damage. Similar results were seen when the study was conducted on mice with transplanted human genes.
Campbell said that increased fetal hemoglobin directly correlates with decreased disease mortality rates.
“Those who have higher fetal hemoglobin levels associate with significant decrease in death and definitely in morbidity and complications,” Campbell said.
Currently there is only one drug, Hydroxyurea — which is also used in cancer treatments — that is FDA approved to increase fetal hemoglobin levels in sickle cell patients. However, the side effects of the drug are not well known.
Campbell said the study will allow an alternative method to treat the disease that might be more favorable.
“There’s a lot of intolerance in some patients in taking (Hydroxyurea),” Campbell said. “… They need other options, so we’re just discovering another protein. This is a protein, and it’s in the body.”
The study was a collaborative effort by different University departments, Campbell said. Osamu Tanabe, a research assistant professor of cell and developmental biology, and James Engel, a cell and developmental biology professor and department chair, were co-authors and contributors to the study.
In 2007, Tanabe first developed the gene that caused the over-expression of TR2 and TR4 proteins and proposed the study on mice to Campbell.
Now, the researchers will begin to translate these findings into a treatment safe for humans. Tanabe said it could take a long time, but the next step is to find a way to cause the same effects seen in the mice by increasing the activation of TR2 and TR4 receptors, which may lead pharmacological researchers to develop a drug that can do this.
“(I think) our findings may lead to a new therapeutic approach for the disease,” Tanabe said.