Timothy Joseph McMahon, MD, PhD

Professor of Medicine
Campus mail Duke Box 103003, MSRB II, Durham, NC 27710
Phone (919) 668-7762
Email address tim.mcmahon@duke.edu

The McMahon Lab at Duke University and Durham VA Medical Center is investigating novel roles of the red blood cell (RBC) in the circulation. The regulated release of the vasodilator SNO (a form of NO, nitric oxide) by RBCs within the respiratory cycle in mammals optimizes nutrient delivery at multiple levels, especially in the lung (gas exchange) and the peripheral microcirculation (O2 transport to tisses). Deficiency of RBC SNO bioactivity (as in human RBCs banked for transfusion), for example, appears to contribute to the serious lung and circulatory problems associated with RBC transfusion in some settings. We have also demonstrated benefit in the use of treatments that exploit RBCs as a vehicle for delivery of SNOs, in both human patients and in model animals.

RBCs also release ATP in response to stimuli including deformation and hypoxia, and the exported ATP also participates in the maintenance of a healthy circulation, according to mechanisms that we are now unraveling.

We use basic and translational approaches to understand the molecular mechanisms by which these RBC-derived signals effect circulatory changes in human health and disease, particularly in the lung. Disease states driving this research include acute and chronic lung diseases such as sepsis (severe infection), transfusion-related respiratory problems, sickle cell disease, and pulmonary hypertension of adults and newborns.

Funding: VA and NIH.

Education and Training

  • Pulmonary Fellow, Medicine, Duke University, 1996 - 1999
  • Medical Resident, Medicine, Duke University, 1993 - 1996
  • M.D., Tulane University, 1993
  • Ph.D., Tulane University, 1992

Publications

McMahon, TJ, and Bryan, NS. "Biomarkers in Pulmonary Vascular Disease: Gauging Response to Therapy." The American journal of cardiology 120, no. 8S (October 2017): S89-S95. (Review)

PMID
29025575
Full Text

Dosier, LBM, Premkumar, VJ, Zhu, H, Akosman, I, Wempe, MF, and McMahon, TJ. "Antagonists of the system L neutral amino acid transporter (LAT) promote endothelial adhesivity of human red blood cells." Thrombosis and haemostasis 117, no. 7 (June 2017): 1402-1411.

PMID
28382373
Full Text

Pastva, AM, Walker, JK, Maddox, LA, Mukherjee, S, Giamberardino, C, Hsia, B, Potts, E, Zhu, H, Degan, S, Sunday, ME, Lawson, BL, Korfhagen, TR, Schwartz, DA, Eu, JP, Foster, WM, McMahon, TJ, Que, L, and Wright, JR. "Nitric Oxide Mediates Relative Airway Hyporesponsiveness to Lipopolysaccharide in Surfactant Protein A-Deficient Mice (Retraction of vol 44, pg 175, 2011)." AMERICAN JOURNAL OF RESPIRATORY CELL AND MOLECULAR BIOLOGY 55, no. 5 (November 2016): 758-758.

Scholars@Duke

Riccio, DA, Malowitz, JR, Cotten, CM, Murtha, AP, and McMahon, TJ. "S-Nitrosylated fetal hemoglobin in neonatal human blood." Biochemical and biophysical research communications 473, no. 4 (May 2016): 1084-1089.

PMID
27060546
Full Text

Swaminathan, AC, Poms, A, Kennedy, K, Zhu, H, Gaspard, E, Fortin, TA, Senick, J, Parikh, K, Kelleher, ZT, Fee, B, Rajagopal, S, Murray, K, Tapson, V, McMahon, TJ, and Circulation, P. "Toward Theranostic Biomarkers In Pulmonary Hypertension." 2016.

Scholars@Duke

Dosier, LBM, Zhu, H, and McMahon, TJ. "Inhibition Of L-Type Amino Acid Transporter 1 (lat-1) Export Of S-Nitrosothiols (sno) Promotes Red Blood Cell Adhesion To Endothelial Cells." 2016.

Scholars@Duke

McMahon, TJ. "Platelets promote pulmonary pull of polys." Blood 126, no. 19 (November 2015): 2174-2175.

PMID
26542252
Full Text

Riccio, DA, Zhu, H, Foster, MW, Huang, B, Hofmann, CL, Palmer, GM, and McMahon, TJ. "Renitrosylation of banked human red blood cells improves deformability and reduces adhesivity." Transfusion 55, no. 10 (October 2015): 2452-2463.

PMID
26098062
Full Text

Kirby, BS, Schwarzbaum, PJ, Lazarowski, ER, Dinenno, FA, and McMahon, TJ. "Liberation of ATP secondary to hemolysis is not mutually exclusive of regulated export." Blood 125, no. 11 (March 2015): 1844-1845. (Letter)

PMID
25766567
Full Text

Riccio, DA, Zhu, H, Foster, MW, Huang, B, Hofmann, CL, Palmer, GM, and McMahon, TJ. "Renitrosylation of banked human red blood cells improves deformability and reduces adhesivity." Transfusion 55, no. 10 (2015): 2452-2463.

Full Text

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