Nephrology Faculty Research Activities

Carlton M. Bates, MD
Dr. Bates has NIH-funded studies on the role of fibroblast growth factor receptors (Fgfrs) and their signaling adapter proteins in the developing kidney using the mouse as a model. These studies are very clinically relevant given that congenital abnormalities of the urinary tract are responsible for the majority of cases of chronic kidney disease in children. Using various gene targeting approaches, the laboratory has revealed how Fgfrs and their adapters are critical for patterning of different renal lineages and are necessary at both early and later stages of kidney development. The Bates laboratory has also generated genetic mouse mutants that develop vesicoureteral reflux and reflux nephropathy which is also very clinically relevant given that this is the 4th leading cause of chronic kidney disease in children. The laboratory also actively collaborates with other investigators in a genetic mouse model of obstructive nephropathy due to absence of bladder detrusor muscle. The future plans are to determine the molecular pathways through which many of the Fgfr signaling defects occur. These approaches may lead to new biomarkers and therapeutic targets for congenital kidney disease.

Demetrius Ellis, MD
Dr. Ellis’ research interests include diabetic nephropathy, pediatric hypertension, sleep and fatigue assessment of children and adolescents with chronic kidney disease, and pediatric transplantation. Dr. Ellis’ research is supported in part by an NIH grant in collaboration with Dr. Trevor Orchard (Epidemiology of Diabetes Complications, Phase II., DK34818-20) and the Norman S. Coplin Foundation in collaboration with Dr. Mark Unruh (Sleep and fatigue in children and adolescents with CKD).

Jacqueline Ho, MD
Dr. Ho’s major research interests are in defining the requirement for miRNAs in kidney progenitor cells during renal development, and in the regulation of podocyte structure and function during proteinuric kidney diseases. miRNAs represent a fundamentally new means of controlling gene expression and have been implicated in the regulation of diverse developmental processes. Her previous work demonstrated a critical role for miRNAs in the regulation of kidney progenitor survival during development, and in the maintenance of podocyte structure. Current work in her laboratory is focused on the identification of specific miRNAs, and their mRNA targets, that mediate these effects. Her research is supported by an NIH grant, the Norman S. Coplon Extramural Grant Program and intramural funds.

Yosuke Miyashita, MD, MPH
Dr. Miyashita’s research interest is in pediatric hypertension. He is currently in the process of implementing Ambulatory Blood Pressure Monitoring at Children’s Hospital of Pittsburgh of UPMC. He plans on a number of clinical research projects using ABPM data including partnership with the Weight Management Clinic and solid organ transplant programs.

Michael Moritz, MD
Dr. Moritz has research interests on the epidemiology and treatment of dysnatremias in children. He introduced the concept of using 0.9% sodium chloride in maintenance parenteral fluids for the prevention of hospital-acquired hyponatremia, and he has been an outspoken advocate for this therapy. This has resulted in a worldwide change in medical practice in both children and adults. Dr. Moritz is an internationally recognized expert in the controversial topic of salt poisoning in children and has served as a medical expert in high profile trials in the UK and US. He has also conducted seminal work in the epidemiology and prevention of breast-feeding associated hypernatremia. Dr. Moritz is Clinical Director of the Division of Nephrology and the Medical Director of Children’s Hospital of Pittsburgh Pediatric Dialysis Unit. He was the first to report on bleeding complications from high concentration heparin to pack hemodialysis catheters in children. His specific research interests include disorders in sodium and water metabolism (central pontine myelinolysis, hyponatremic encephalopathy, hypernatremic dehydration, salt poisoning, fluid therapy), hemodialysis access in children, and pediatric hypertension trials.

Agnieszka Swiatecka-Urban, MD
Dr. Swiatecka-Urban’s major research interests are in elucidating the spacial and temporal regulation of transmembrane protein trafficking in polarized epithelial cells. The first NIH funded project is to understand the regulation of the endocytic trafficking of cystic fibrosis transmembrane conductance regulator (CFTR). The CFTR is a cAMP-activated Cl-channel that mediates transepithelial Cl-transport in many tissues including the airway and kidney. Dr. Urban studies the interactions between CFTR and Rab GTPases, unconventional myosin motors, and other endocytic adaptors including members of the ubiquitin family. The second major NIH funded project is to elucidate the role of nephrin trafficking in maintaining the dynamic structure of the glomerular slit diaphragm (pathomechanisms of nephrotic syndrome). Nephrotic syndrome is a very common kidney disease in children and adults. The pathomechanism of nephrotic syndrome is not well understood and remains one of the most important questions in nephrology today. Podocytes, the visceral glomerular epithelial cells, form a close-fitting network of interdigitating cellular extensions – foot processes – linked by modified tight junctions called slit diaphragms. Nephrin is a transmembrane protein which is critically important for the integrity of the slit diaphragm and mutations in the nephrin gene are responsible for many forms of congenital nephrotic syndrome. Dr. Urban studies the role of nephrin trafficking in maintaining the dynamic structure of the filtration barrier in the kidney.