CIB2 in the retina: cell types, function and molecular mechanism
Saumil S. Sethna, PhD
University of Maryland
School of Medicine
Dr. Sethna joined the lab of Zubair M. Ahmed, PhD, in the Department of Otolaryngology – Head & Neck Surgery at the University of Maryland in March 2015, working as a research fellow. The main focus of research in Dr. Ahmed’s lab is Usher syndrome, an autosomal recessively inherited disorder characterized by deaf-blindness. In 2012, Dr. Ahmed’s lab reported mutation in Cib2 (an encoded calcium-binding regulatory protein that interacts with DNA-dependent protein kinase catalytic subunits and is involved in photoreceptor cell maintenance), causing Usher syndrome type I in humans. Since that time, Dr. Sethna has presented data revealing that Cib2 knockout mice have progressive loss of retinal function, and pathophysiology in the retinal pigment epithelium (RPE), including defects in phagocytosis. From this, Dr. Sethna hypothesized that loss of Cib2 leads to RPE Ca++ (calcium) imbalance that perturbs OS (outer segment) phagocytosis, RPE pathology and PR (photoreceptor) functional defects.