department of pharmacology

Thomas Kelley, Ph.D.

kelley

Associate Professor

Phone: (216) 368 0831
Fax: NA
E-mail: tjk12@cwru.edu

Research

* Identifying a mechanistic link between the loss of CFTR function and altered cell-signaling control in CF airway epithelial cells – It is unclear how a loss of CFTR function influences signal transduction cascades. As described above, the GTPases seem to be a common link between two of these signaling abnormalities. We have identified increased expression of the GTPase RhoA in CF epithelial cells and are interested in exploring the GTPase regulatory pathways in order to explain these signaling phenomenon in CF. Our current focus is an examination of the isoprenoid/cholesterol synthesis pathway. Many CF-related characteristics can be explained by an increase in isoprenoid synthesis and there is an association between cholesterol regulation and the ATP binding cassette (ABC) proteins, a class of proteins that includes the CFTR. The immediate goal of this project is to characterize the regulation of the isoprenoid/cholesterol synthesis pathway in CF epithelial cells in order to identify the mechanism by which CFTR function influences cell signaling cascades.

* Determining cell signaling consequences of impaired intracellular cholesterol transport - These studies focus primarily on elucidating the consequences of lost NPC1 function in Niemann-Pick type C disease, a pediatric neurological disorder. This project is related to our CF studies as it appears that similar signaling alterations are taking place in affected cell types of both diseases. We have identified impaired induction of NOS2 expression and elevated RhoA expression in NPC models that are directly mediated by lesions in cholesterol processing pathways. These studies are also applicable to understanding related processes in atherosclerotic disease.

* The regulation of Smad3 expression as a modulator of fibrotic disease – Smad3 is a signaling protein involved in mediating the effects of the transforming growth factor–b1 (TGF-b1). We have observed a reduced expression of Smad3 in CF airway epithelial cells and have pursued a study of regulatory mechanisms that may explain this observation. We have developed a human Smad3 promoter reporter construct that drives the expression of luciferase as a method to examine signaling elements important to influencing Smad3 expression. These studies have revealed the importance of the isoprenoid pathway, a branch of the cholesterol synthesis cascade. One use of isoprenoids is the modification of small GTPase proteins including Ras and Rho GTPases, and the role of these proteins in Smad3 regulation is being explored. We have also determined that a protein involved in mitogen activated protein kinase activation is essential in maintaining Smad3 promoter function. An inhibitor of this protein, MEK1, significantly inhibits Smad3 promoter function, apparently through an Sp1-dependent mechanism. Identifying other modes of Smad3 promoter regulation and determining methods of modulating the severity of fibrotic diseases by manipulating Smad3 expression are the current objectives of this project.

SELECTED REFERENCES:

Perez A, Issler AC, Cotton CU, Kelley TJ, Verkman AS, Davis PB. "CFTR inhibition mimics the cystic fibrosis inflammatory profile" Am J Physiol Lung Cell Mol Physiol. 2006 Aug 18;

White NM, Corey DA, Kelley TJ. "Mechanistic Similarities between Cultured Cell Models of Cystic Fibrosis & Niemann-Pick Type C" Am J Respir Cell Mol Biol. 2004 Nov;31(5):538-43

Lee JY, Elmer HL, Ross KR, Kelley TJ. "Isoprenoid-mediated control of SMAD3 expression in a cultured model of cystic fibrosis epithelial cells" Am J Respir Cell Mol Biol. 2004 Aug;31(2):234-40

Kreiselmeier NE, Kraynack NC, Corey DA, Kelley TJ. "Statin-mediated correction of STAT1 signaling and inducible nitric oxide synthase expression in cystic fibrosis epithelial cells" Am J Physiol Lung Cell Mol Physiol. 2003 Dec;285(6):L1286-95

Kraynack NC, Corey DA, Elmer HL, Kelley TJ. "Mechanisms of NOS2 regulation by Rho GTPase signaling in airway epithelial cells" Am J Physiol Lung Cell Mol Physiol. 2002 Sep;283(3):L604-11

Ziady AG, Kelley TJ, Milliken E, Ferkol T, Davis PB. "Functional evidence of CFTR gene transfer in nasal epithelium of cystic fibrosis mice in vivo following luminal application of DNA complexes targeted to the serpin-enzyme complex receptor" Molecular Therapy 5(4):413-9, 2002

Kelley TJ, Elmer HL, Corey DA. "Reduced Smad3 protein expression and altered transforming growth factor-beta1-mediated signaling in cystic fibrosis epithelial cells" Am J Respir Cell Mol Biol. 2001 Dec;25(6):732-8

Brady KG, Kelley TJ, Drumm ML. "Examining basal chloride transport using the nasal potential difference response in murine model" Am J Physiol Lung Cell Mol Physiol. 281(5):L1173-9, 2001

Mhanna MJ, Ferkol T, Martin RJ, Dreshaj IA, van Heeckeren AM, Kelley TJ, Haxhiu MA. "Nitric oxide deficiency contributes to impairment of airway relaxation in cystic fibrosis mice" Am J Respir Cell Mol Biol. 2001 May;24(5):621-6

Kelley TJ, Elmer HL. "In vivo alterations of IFN regulatory factor-1 and PIAS1 protein levels in cystic fibrosis epithelium" J Clin Invest. 2000 Aug;106(3):403-10

Kelley TJ, St Amand T, Groll JM, Ray S, Basu S. "DNA polymerase-associated lectin (DPAL) and its binding to the galactose-containing glycoconjugate of the replication complex" Biosci Rep. 1999 Oct;19(5):433-47

Elmer HL, Brady KG, Drumm ML, Kelley TJ. "Nitric oxide-mediated regulation of transepithelial sodium and chloride transport in murine nasal epithelium"
Am J Physiol. 276(3 Pt 1):L466-73, 1999

Kelley TJ, Drumm ML. "Inducible nitric oxide synthase expression is reduced in cystic fibrosis murine and human airway epithelial cells" J Clin Invest. 102(6):1200-7, 1998