Research interest:
Unchecked proliferation can compromise organ function and tissue perfusion. My laboratory's interests lie in utilizing animal models of proliferative disease (e.g. glomerulonephritis, arterial balloon-injury) to study intracellular signal transduction cascades involved in the regulation of proliferation.
Specifically, one target of interest is the role of the dual-specificity phosphatase, MKP-3 and its regulation of the mitogen-activated protein kinase, ERK. ERK is potently activated by growth factors like platelet-derived growth factor (PDGF), a major factor suggested to be involved in these proliferative disorders. Upon phosphorylation on threonine and tyrosine residues, ERK is activated and phosphorylates cytosolic and nuclear targets. Translocation to the nucleus suggests a role for ERK in the regulation of transcription factors necessary for gene expression. MKP-3 is a cytosolically-localized enzyme and has been shown to specifically interact with ERK via an N-terminal binding domain. One goal of my laboratory is to investigate the use of adenoviral-delivered MKP-3 as a molecular inhibitor of PDGF-induced ERK phosphorylation and subsequent proliferation of primary mesangial and smooth muscle cells as a first step toward application to animal models of proliferative disease. A combination of integrated molecular biological, pharmacological, biochemical and physiological approaches are used.
Fetal bovine serum (FBS) stimulates the time dependent phosphorylation of ERK in bovine coronary smooth muscle cells. Bovine coronary smooth muscle cells were cultured on 4-well chamber slides, serum restricted for 24 hr (A) and then stimulated for (B) 5 min, (C) 15 min or (D) 60 min with 10% FBS. The cells were fixed in 10% paraformaldehyde and incubated with monoclonal anti-phospho-ERK antibodies overnight. The following day the cells were washed and incubated with goat-anti–mouse Texas Red secondary antibody for 1 hr. Images were taken with a Nikon Eclipse fluorescence microscope with a Slider RT CCD camera using SPOT advanced imaging software. Magnification = 400X.
Recent Publications
Dulin, N.O., Pratt, P.F., Tiruppathi, C., Niu, J., Voyno-Yasenetskaya, T., and Dunn, M.J. Regulator of G protein signaling RGS3T is localized to the nucleus and induces apoptosis. J. Biol. Chem, 275:21317-21323, 2000.
Nithipatikom, K., Pratt, P.F., and Campbell, W.B. Determination of epoxyeicosatrienoic acids using microbore liquid chromatography with fluorescence detection. Am. J. Physiol, 279:H857-H862, 2000.
Fryer, R. M., Pratt, P. F., Hsu, A. K., and Gross, G. J. Differential activation of extracellular signal regulated kinase isoforms in preconditioning and opioid-induced cardioprotection. J. Pharmacol. Exp. Ther., 296:647-654, 2001.
Pratt PF., Li P. Hillard CJ. Kurian J. Campbell WB. Endothelium-independent, ouabain-sensitive relaxation of bovine coronary arteries by EETs. Am. J. Physiol., 280(3):H1113-H1121, 2001
Foschi, M., Sorokin, A., Pratt, P., McGinty, A., La Villa, G., Franchi, F., and Dunn, M.J. Preproendothelin-1 expression in human mesangial cells: Evidence for a p38 mitogen activated protein kinase/protein kinase-C dependent mechanism. J. Amer. Soc. Nephr. 12(6):1137-1150, 2001.
Pratt, P.F., Bonnet, S., Ludwig, L., Bonnet, P. and Rusch, N.J. Upregulation of L-type Ca2+ channels in mesenteric and skeletal arteries of SHR. Hypertension 40:214-219, 2002.