Spotlight on Justine Renauld, PhD
Assistant Professor at Creighton University School of Medicine
Article by Matsya Thulasiram
“Blindness separates people from things; deafness separates people from people.”
This quote from Helen Keller has impacted the scientific journey of recently appointed Assistant Professor, Dr. Justine Renauld. Renauld’s fascination with the inner ear began during her master’s degree. “I really liked the inner ear…the fact that it is a spiral and everything is perfectly organized, I was hooked. I also liked the idea of helping people recover hearing loss.” Her work throughout her graduate studies was on the development of the cytoskeleton, the structural network of a cell, in support cells of the cochlea. Her focus shifted during her postdoctoral fellowship when she directed her attention towards the stria vascularis, the part of the cochlea which maintains the proper environment that is required for hearing function.
Focus on the stria vascularis; how stress hormones affect the environment of the ear
As a postdoc at Case Western Reserve University, Renauld started investigating the stria vascularis to develop therapies to treat congenital deafness, such as Waardenburg syndrome. Throughout her fellowship, Renauld began to think about other forms of hearing loss that effected the stria vascularis, specifically Meniere’s disease. While the exact cause of Meniere’s disease is unknown, characteristics of disease onset and progression include the irregular modulation of endolymph, the fluid that fills the inner ear. Since one of the triggers of Meniere’s disease is the exacerbation of stress, Renauld is interested in understanding the impact of stress on the regulation of endolymph composition and stability, in other words, homeostasis. “Some stress hormones from the adrenal glands can influence the secretion of ions”, Renauld explains. “I want to try and understand the adrenergic receptors in the ear and how different types of stress responses influence endolymph homeostasis”.
Using two techniques
Renauld plans to approach her research question with two techniques: she will use in vitro ion marker recording, which is a technique used to visually trace ions within the cells, and she will use ion-sensitive microelectrodes to directly measure ion concentration. By using both a visual imaging technique and a quantitative electrophysiological technique, Renauld builds a comprehensive method to develop the foundation of her work as a new Principle Investigator at Creighton University. Renauld reflects that her AHRF funding allowed her to really develop the details of her study. “It was a big part of why I was able to secure a faculty position”.
Implications for Meniere’s disease treatment
The implications of Renauld’s work are directly applicable to patients facing Meniere’s disease. There are no treatments available for Meniere’s disease to date, but Renauld points out that there are already numerous FDA-approved treatments that target adrenergic receptors. Therefore, by pinpointing the specific adrenergic receptors involved in stress-induced responses within the ear, Renauld’s research opens the door to testing readily available clinic-based treatments.
This article was contributed by Matsya Thulasiram, PhD candidate at the University of Toronto.