Tianxin Yang M.D.,Ph.D.Associate Professor of Medicine Phone: 801-581-6709
Fax: 801-581-4343
tianxin.yang@hsc.utah.edu Office:
4C 104
School of Medicine
30 North 1900 East
Salt Lake City, UT 84132
Research Interests Dr. Yang’s long term interests are† the role of arachidonic acid metabolites and other lipid-derived products in regulation of renal function, related to† sodium balance and blood pressure regulation. The current emphasis is on characterizing renal function of cyclooxygenase-2 (COX-2) and peroxisome proliferator-activated receptor gamma (PPARg)† and thus there are two lines research: 1) Renal function of COX-2. COX-2 is expressed in distinct cell types in the kidney involved in regulation of a wide spectrum of renal functions.† Macula densa COX-2 is induced by low salt and involved in regulation of renin secretion and vascular tone while renal medullary COX-2 is induced by high salt and possibly involved in promoting salt excretion and stabilizing blood pressure. Therefore, two series of studies are being pursued: a) Elucidation of the role and mechanism of COX-2 in regulation of renin secretion.† This will be achieved by examining the interaction of COX-2 and nNOS in the macula densa cells. The interaction between the two pathways is examined in vivo using nNOS -/- and COX-2 -/- mice and in vitro using a mouse macula densa derived cell line; b) Investigation of the role and mechanism of high salt-induced renal medullary COX-2 expression† in regulation of sodium balance and blood pressure. Chronic intramedullary infusion techniques are currently used to examine whether site-specific COX-2 inhibition in renal medulla produces salt sensitive hypertension. Interactions between renal medullary COX-2 with other local factors, such as nitric oxide and endothelins, are also† being examined. 2) Renal and vascular functions of PPARg. PPARg is† a novel nuclear receptor, controlling† expression of a range of target genes through interaction with PPAR responsive elements.† PPARg ligands (thiazolidinediones) cause edema due to with fluid retention, yet the mechanism is not fully known. Knockout of PPARg in the collecting duct abrogates the fluid retention; these knockout mice are being used explore the molecular mechanisms of PPARg in regulation of sodium balance and blood pressure. Recent Publications Yang T, Huang Y, Ye W, Hansen P, Schnermann J, and Briggs JP. Influence of genetic background and gender on hypertension and renal failure in COX-2-deficient mice. Am J Physiol-Renal 288:F1125-32, 2005 Zhang A, Ding G, Huang S, Wu Y, Pan X, Guan X, Chen R, and Yang T. c-Jun NH2-terminal kinase mediation of angiotensin II-induced proliferation of human mesangial cells. Am J Physiol-Renal 288:F1118-24, 2005 Yang T, Zhang A, Mizel D, Briggs JP, and Schnermann JB. Hypertonic induction of COX-2 in collecting duct cells by reactive oxygen species of mitochondrial origin. J Biol Chem 280:34966-73, 2005 Zhang H, Zhang A, Donald E. Kohan DE, Nelson RD, Gonzalez FJ, and Yang T. Collecting-duct-specific deletion of PPARγ blocks thiazolidinedione-induced fluid retention. Proc Natl Acad Sci U SA 102:9406-9411, 2005 Sakuma Y, Nonoguchi H, Takayama M, Yang T, Terada Y, Inoue T. Nakayama Y, Kohda Y, Sasaki S, and Tomita K. Differential effects of hyperosmolality on Na-K-ATPase and vasopressin-dependent cAMP generation in the medullary thick ascending limb and outer medullary collecting duct. Hypertens Res. 28:671-9, 2005 Paliege A, Pasumarthy A, Mizel D, Yang T, Schnermann J, and Bachmann S. Effect of apocynin treatment on renal expression of COX-2, NOS1, and renin in Wistar-Kyoto and spontaneously hypertensive rats. Am J Physiol Regul Inter Comp Physiol 290: R694-700, 2006 Ye W, Zhang H, Hillas E, Lalouel JM, Miller RL, Nelson RD, and Honeggar M, and Yang T. Expression and function of COX isoforms in the renal medulla: evidence for regulation of salt sensitivity and blood pressure. Am J Physiol-Renal 290: F542-9, 2006 Guo X and Yang T. Endothelin B receptor antagonism in the rat renal medulla reduces urine flow rate and sodium excretion. Experimental Biology and Medicine 231:1001-5, 2006 Yang T, Zhang A, Pasumarthy A, Warnock Z, and Schnermann JB. Nitric oxide stimulates COX-2 expression in cultured collecting duct cells through MAP kinases but not cGMP. Am J Physiol-Renal 291:F891-5, 2006 Zhang A, Wang M-H, Dong Z, and Yang T. Prostaglandin E2 is a potent inhibitor of epithelial-to-mesenchymal transition: Interaction with hepatocyte growth factor. Am J Physiol-Renal 291:F1323-31, 2006 Zhang A, Dong Z, and Yang T. Prostaglandin D2 inhibits epithelial-to-mesenchymal transition in cultured MDCK cells. Am J Physiol-Renal 291:F1332-42, 2006 Jia Z, Zhang A, Zhang H, Dong Z, and Yang T. Deletion of microsomal prostaglandin E synthase-1 increases sensitivity to salt loading and angiotensin II infusion. Cir. Res. 99:1243-51, 2006 Jiang M, Wei Q, Pabla N, Dong G, Wang CY, Yang T, Smith SB, and Dong Z. Effects of hydroxyl radical scavenging on cisplatin-induced p53 activation, tubular cell apoptosis and nephrotoxicity. Bichem Pharmacol 73:1499-1510, 2007 Brooks C, Wang J, Yang T, and Dong Z. Characterization of cell clones isolated from hopoxia-selected renal proximal tubular cells. Am J Physiol-Renal 292:F243-52, 2007 Jiang M, Pabla N, Murphy RF, Yang T, Yin XM, Degenhardt K, White E, and Dong Z. Nutlin-3 protect kidney cells during cisplatin therapy by suppressing Bax/Bak activation. J Biol Chem 282:2636-45, 2007 Huang H, Morisseau C, Wang J, Yang T, Falck J, Hammock B, Wang M-H. Increasing or stabilizing renal epoxyeicosatrienoic acid production attenuates abnormal renal function and hypertension in obese Rats. Am J Physiol-Renal 293:F342-9, 2007 Zhang A, Jia Z, Guo X, and Yang T. Aldosterone induces epithelial-mesenchymal transition via ROS of mitochondrial origin. Am J Physiol-Renal 293:F723-31, 2007 Ge Y, Strait KA, Stricklett PK, Yang T, and Kohan DE. Role of prostaglandins in collecting duct-derived endothelin-1 regulation of blood pressure and water excretion. Am J Physiol-Renal 293:F1805-10, 2007 Soodvilai S and Yang T. Hydrogen peroxide stimulates chloride secretion in primary inner medullary collecting duct cells via mPGES-1-derived PGE2. Am J Physiol-Renal 293:F1571-6, 2007 Ding G, Zhang A, Huang S, Pan X, Chen R, and Yang T. Angiotensin II induces c-Jun NH2-terminal kinase activation and proliferation of human mesangial cells via redox-sensitive transactivation of the EGF receptor. Am J Physiol-Renal 293:F1889-97, 2007 Liu H, Ye W, Guan G, Jia Z, and Yang T. Developmental regulation of calcineurin isoforms in the rodent kidney: association with COX-2. Am J Physiol-Renal 293:F1898-904, 2007 |
