Cathy L. Mendelsohn, PhD

Current Research
Our work is focused on understanding how the urogenital system forms, and on identifying the cause of urogenital malformations first in rodent, then in human models.

We are currently pursuing two types of projects both aimed at understanding urogenital tract development. i. investigating the molecular and cellular events important for formation of connections between the ureter and the bladder. ii. studying the role of renal stroma in patterning the embryonic kidney.


Normal ureter connected to the bladder in an e12 mouse embryo-ureter/Wolffian ducts are green (Hoxb7-Gfp) and bladder is red (cytokeratin)	Duplicated ureter similar to malformations seen in humans, induced by vitamin A excess during gestation. Picture shows ureter/kidney in Green (Hoxb7-Gfp mice) and bladder in Red (uroplakin

Selected Publications
1. Levinson R, Mendelsohn C. Stromal progenitors are important for patterning epithelial and mesenchymal cell types in the embryonic kidney. Semin Cell Dev Biol. 2003 Aug;14(4):225-31. Review.

2. Batourina E, Choi C, Paragas N, Bello N, Hensle T, Costantini FD, Schuchardt A, Bacallao RL, Mendelsohn CL. Distal ureter morphogenesis depends on epithelial cell remodeling mediated by vitamin A and Ret. Nat Genet. 2002 Sep;32(1):109-15. Erratum in: Nat Genet 2002 Oct;32(2):331.

3. Clark L, Wei M, Cattoretti G, Mendelsohn C, Tycko B. The Tnfrh1 (Tnfrsf23) gene is weakly imprinted in several organs and expressed at the trophoblast-decidua interface. BMC Genet. 2002 Jun 27;3(1):11.

4. Batourina, E., Gim, S., Bello, N., Claggett-Dame, M., Srinivas, S., Costantini, F. and Mendelsohn, C. (2001) Vitamin A controls epithelial/mesenchymal interactions via ret expression. Nature Genetics 27, 74-77.

5. Mendelsohn, C.*, Batourina, K., Fung, S., Gilbert, T. and Dodd, J. Stromal cells mediate retinoid-dependent functions essential for renal development. (1999). Development 126, 1139-1148.

6. Paik J, During A, Harrison EH, Mendelsohn CL, Lai K, Blaner WS. Expression and characterization of a murine enzyme able to cleave beta-carotene. The formation of retinoids. J Biol Chem. 2001 Aug 24;276(34):32160-8.

Current Projects
1. Molecular Events in Urinary Tract Formation
We will use mouse models of Vitamin A deficiency and time-lapse photography in organ culture studies to investigate how vitamin A induces wedge formation, and how wedge formation controls vertical and lateral displacement of the distal ureter. To define the role of the primitive bladder in these events, we will generate a new transgenic model in which Wolffian duct derivatives and the primitive bladder are differentially labeled with non-overlapping chromophores, enabling us to visualize their respective interactions in living tissue. Finally, we will use a Cre/loxP mediated recombination system to mark cells wedge cells and their descendents to test the hypothesis that the wedge is a primordium of the trigone, a tissue integral to the bladder crucial for urine storage. The focus of this proposal is to elucidate normal mechanisms underlying ureter insertion into the bladder.
National Institute of Diabetes and Digestive and Kidney Diseases
9/2003-8/2008

Keywords
growth /development, retinoid, ureter, urinary tract, apoptosis, biological signal transduction, chromophore, disease /disorder model, mesenchyme, model design /development, urinary bladder, fluorescence microscopy, laboratory mouse, organ culture, photography, terminal nick end labeling, time resolved data, transfection /expression vector, transgenic animal