835 S. Wolcott Ave., (M/C 901)
Chicago, IL 60612-7342
312-996-7620 phone
312-996-1414 fax

Mrinalini C. Rao, PhD
Professor

Research in Dr. Rao's laboratory focuses on elucidating the molecular mechanisms underlying hormonal and neurotransmitter mediated regulation of physiological processes, in particular, those modulating ion transport across epithelial cells. The major emphasis is on the gastrointestinal tract, where such studies help elucidate the basis of diseases ranging from infectious diarrheas to inflammatory bowel disease and cystic fibrosis (CF). In general, epithelial ion transport processes are complex and are involved in the vectorial movement of salt and water as well as in routine cellular functions such as the regulation of growth, volume and pH.

This laboratory has been successful in establishing primary cultures of human and rabbit colonic epithelia, considered a difficult task, since intestinal epithelial cells do not lend themselves readily to isolation and culture. This has facilitated the study of various ion transporters including chloride channels, such as the cystic fibrosis transmembrane conductance regulator (CFTR), the sodium-potassium-chloride cotransporter (NKCC) and the sodium/hydrogen exchangers (NHE). Examination of the regulation of these transporters by cAMP, cGMP and calcium signal transduction cascades is a primary focus of this laboratory. For example, this laboratory has demonstrated the presence of second messenger-specific protein kinases and CFTR in the human colon and that the colon of CF subjects exhibits impaired Cl- transport in response to cAMP-, cGMP- and calcium stimulation. This laboratory has also demonstrated the expression of genes involved in ion transport in mammary epithelial cells. In addition, mammotropic hormones, such as prolactin, have been shown to modulate sodium and chloride transport in these cells.

Recent efforts in the laboratory are concentrated on the exciting new areas of compartmentalization, including the study of scaffolding proteins and of cross-talk between various signaling pathways. For example, changes in cGMP and calcium signaling have been observed during development in the colon. The precise site/step of this differential regulation has been identified to the lack of appropriate expression of specific gene products in the signaling cascade. Two exciting candidates are the localization of phospholipase C and the expression of protein kinase C delta. An elucidation of the individual molecular events will help in the understanding of the molecular basis of varied physiological processes such as milk production and intestinal secretions.