Brian T. O’Neill is an Associate Professor and Program Director for the Endocrinology Fellowship at the University of Iowa.  He received his MD/PhD from the University of Utah, where he completed his thesis work with Dr. E. Dale Abel.  Dr. O’Neill then did endocrinology fellowship at Beth Israel Deaconess Medical Center, affiliates of Harvard Medical School and post-graduate training under the mentorship of Dr. C. Ronald Kahn at the Joslin Diabetes Center.

Dr. O’Neill’s seminal contributions to FoxO biology include the discovery that FoxO transcription factors regulate coordination of muscle growth and energy production by insulin and IGF-1 signaling.  Decreased muscle strength is an under-appreciated complication of uncontrolled diabetes, which can lead to impaired recovery after surgery or severe illness.  In work by Dr. Gourav Bhardwaj published in JCI 2021 and Frontiers in Physiology 2022, the O’Neill lab showed loss of insulin action in diabetes or by genetic deletion of IR and IGF-1R causes decreased mitochondrial respiration and ATP production by FoxO-induced repression of OXPHOS genes.  Furthermore, a publication by Christie Penniman in JCSM 2022 showed deletion of FoxOs also prevents aging-related decline in muscle strength and mitochondrial metabolism by suppression of atrophy-related genes and increases in OXPHOS. Ongoing work in the O’Neill lab currently seeks to define FoxO targets that modify muscle strength in diabetes, in hopes of identifying novel targets for therapy and to speed recovery in patients with diabetes.  

Currently, Dr. O’Neill serves as the Program Director for the Adult Endocrinology Fellowship at the University of Iowa, training new Endocrinologists each year.  He has co-written the Chapter on Pathogenesis of Type 2 Diabetes Mellitus in the Williams Textbook of Endocrinology 15^th Edition with Dr. C. Ronald Kahn and Dr. Heather Ferris. He also has an appointment at the VA Iowa City with current VA Merit funding.