Renita Horton understands the toll sickle cell disease can have on patients and their families. For more than 30 years, the Lexington native watched her older sister Sanovia battle and ultimately succumb to complications from the disease.
Now an assistant professor of biomedical engineering at Mississippi State University, Horton honors her sister’s memory through research that will help improve outcomes for those still fighting sickle cell disease.
“My mom was told she had the sickle cell trait, but there was no information given to her about the consequences of it,” Horton explained. “It wasn’t until my sister was diagnosed that my family became more familiar with the disease.”
Considered the most common inherited blood disorder in the U.S., sickle cell disease is a genetic mutation within red blood cells that causes the ordinarily round cells to take on an abnormally stiff, crescent shape, which affects how efficiently they transport oxygen throughout the body. However, Horton explained it’s not necessarily the disease itself but rather the cumulative effect it has on a person’s organs and internal structures that causes problems.
“As my sister got older, we started to see more of the effects on her body. She was in the hospital multiple times a year, was on oxygen because of lung issues and was prescribed strong medications,” Horton said. “Seeing the effects sickle cell disease had on my sister and feeling I can relate to patients’ families is what drives my passion to pursue the research I’m doing now.”
ABOVE: Renita Horton, MSU associate professor of biomedical engineering, works with a research team of undergraduate and graduate students to gain a better understanding of the basic mechanisms of cardiovascular disease. Pictured with Horton in MSU’s Cardiovascular Tissue Engineering Laboratory are (top) Jackson B. Coole of Picayune, a senior biological engineering major and 2017 recipient of the Barry Goldwater Scholarship; and (bottom left) Kristen P. Hubbard, a junior chemical engineering major from Pleasant Grove, Alabama. Bottom right: Horton (right) honors the memory of her older sister Sanovia (seated) through research that will help improve outcomes for those still fighting sickle cell disease. Also pictured is Horton’s sister Yolanda.
Following her sister’s death in 2014 at the age of 33, Horton said her interest in cardiovascular research in general and sickle cell disease in particular intensified. At the time, the Mississippi State chemical engineering graduate was finishing a postdoctoral fellowship at Harvard University’s Wyss Institute for Biologically Inspired Engineering. She made the decision to move back to Mississippi following its completion to further her research and be closer to those who help inspire it, including Sanovia’s children, a now 6-year-old girl and 7-year-old boy.
Horton, who holds master’s and doctoral degrees in engineering sciences from Harvard, now leads Mississippi State University’s Cardiovascular Tissue Engineering Laboratory, through which she is working to gain a better understanding of the basic mechanisms of cardiovascular disease. Her research team includes five undergraduate and four graduate students pursuing degrees in chemical engineering, biochemistry and biomedical engineering. It is supported by the Gilbert Memorial Foundation, as well as the university’s Mississippi Agricultural and Forestry Experiment Station’s Strategic Research Initiative.
“The heart contains a number of different cell types, but we’re really interested in the cardiomyocyte, which is responsible for heart contraction and relaxation, allowing it to pump blood to the rest of the body,” Horton said. “We use a number of tools and techniques including microscopes and lasers to examine the features and function of the cardiac tissues and to understand tissue remodeling in response to disease.”
Composed of a clear polymer and glass, small devices called microfluidic chips enable Horton and her team to culture and look at the cardiomyocytes as they contract.
“Essentially, we are able to mimic the structure of the heart to some degree using an organ-on-chip platform,” she said. “By introducing different types of cells to this platform, we can examine potential treatments to see how well they work. Examining organ systems on a cellular level allows us to ask very pointed questions.”
Horton said understanding how cells are affected and organs are damaged could help scientists develop methods to slow or stop the deterioration that occurs over time, which can ultimately improve patient outcomes.
“We discussed a bone marrow transplant for my sister, but because of her condition, including some organ issues, the risk was too high,” Horton said. “I believe the cure will come. My team is interested in understanding how to prevent or reduce organ damage and other issues caused by the disease. I think that can help patients live a better life. Doing research that can be sent out into the world and implemented clinically is how I feel I can make a difference.”
Sickle cell disease is a lifelong battle for those who inherit the disorder. However, Horton said there are things others can do to help them receive treatment for the symptoms.
Infusions of blood from healthy donors can give a sickle cell patient’s organs and muscles a much-needed boost of oxygen, which can help slow organ damage, provide pain relief and help prevent blockages that can lead to stroke.
While blood transfusions can help relieve symptoms, bone marrow transplants have been shown to be curative—most effectively in patients in their early teens.
With both of these treatments, sickle cell patients are dependent on healthy individuals who are willing to donate blood and bone marrow. Horton encourages everyone who can to give blood when they can and to consider registering as a bone marrow donor as it’s important for patients to have fast access to these biological materials—especially when facing a crisis episode with their disease.
As home to the state’s only specialized treatment clinic for patients with sickle cell disease, Horton said the Jackson-based University of Mississippi Medical Center, in conjunction with the Mississippi Sickle Cell Foundation, offers support groups and other helpful resources.
“There are great doctors at UMMC who can advise patients on possible clinical trials or the risks and matching process for those considering a bone marrow transplant,” she said. “The more you know, the better equipped you are.”