Hypoxia pp 401-418 | Cite as

Gene transfer and metabolic modulators as new therapies for pulmonary hypertension

Increasing expression and activity of potassium channels in rat and human models
  • Evangelos D. Michelakis
  • Jason R. B. Dyck
  • M. Sean McMurtry
  • Shaohua Wang
  • Xi-Chen Wu
  • Rohit Moudgil
  • Kyoko Hashimoto
  • Lakshmi Puttagunta
  • Stephen L. Archer
Part of the Advances in Experimental Medicine and Biology book series (AEMB, volume 502)


Chronic Hypoxic Pulmonary Hypertension (CH-PHT) is characterized by pulmonary artery (PA) vasoconstriction and cell proliferation/hypertrophy. PA smooth muscle cell (PASMC) contractility and proliferation are controlled by cytosolic Ca++ levels, which are largely determined by membrane potential (EM). EM is depolarized in CH-PHT due to decreased expression and functional inhibition of several redox-regulated, 4-aminopyridine (4-AP) sensitive, voltage-gated K+ channels (Kv1.5 and Kv2.1). Humans with Pulmonary Arterial Hypertension (PAH) also have decreased PASMC expression of Kv1.5 and Kv2.1. We speculate this “K+-channelopathy” contributes to PASMC depolarization and Ca++ overload thus promoting vasoconstriction and PASMC proliferation. We hypothesized that restoration of Kv channel expression in PHT and might eventually be benefial. Methods: Two strategies were used to increase Kv channel expression in PASMCs: oral administration of a metabolic modulator drug (Dichloroacetate, DCA) and direct Kv gene transfer using an adenovirus (Ad5-Kv2.1). DCA a pyruvate dehydrogenase kinase inhibitor, promotes a more oxidized redox state mimicking normoxia and prevously ahs been noted to increase K+ current in myocytes. Rats were given DCA in the drinking water after the development of CH-PHT and hemodynamics were measured ~5 days later . We also tested the ability of Ad5-Kv2.1 to increase Kv2.1 channel expression and function in human PAs ex vivo. Results: The DCA-treated rats had decreased PVR, RVH and PA remodeling compared to the control CH-PHT rats (n=5/group, p<0.05). DCA restored Kv2.1 expression and PASMC Kv current density to near normoxic levels. Adenoviral gene transfer increased expression of Kv2.1 channels and enhanced 4-AP constriction in human PAs. Conclusion: Increasing Kv channel function in PAs is feasible and might be beneficial.


adenovirus gene therapy Kv1.5 Kv2.1 redox state dichloroacetate and metabolic modulators 


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  1. 1.
    Abenhaim L, Moride Y, Brenot F, Rich S, Benichou J, Kurz X, Higenbottam T, Oakley C, Wouters E, Aubier M, Simonneau G, and Begaud B. Appetite-suppressant drugs and the risk of primary pulmonary hypertension. International Primary Pulmonary Hypertension Study Group. N Engl J Med 335: 609–16, 1996.PubMedCrossRefGoogle Scholar
  2. 2.
    Archer S, and Rich S. Primary Pulmonary Hypertension: A Vascular Biology and Translational Research Work in Progress. Circulation 102: 2781–2791, 2000.PubMedCrossRefGoogle Scholar
  3. 3.
    Archer S, and Rusch N. Potassium Channels in Cardiovascular Biology. Norwell, MA: Kluwer/Plenum Publishing Corporation, 2000 (in press).Google Scholar
  4. 4.
    Archer SL, Huang J, Henry T, Peterson D, and Weir EK. A redox-based O2 sensor in rat pulmonary vasculature. Circ Res 73: 1100–12, 1993.PubMedCrossRefGoogle Scholar
  5. 5.
    Archer SL, Johnson GJ, Gebhard RL, Castleman WL, Levine AS, Westcott JY, Voelkel NF, Nelson DP, and Weir EK. Effect of dietary fish oil on lung lipid profile and hypoxic pulmonary hypertension. J Appl Physiol 66: 1662–73, 1989.PubMedCrossRefGoogle Scholar
  6. 6.
    Archer SL, Souil E, Dinh-Xuan AT, Schremmer B, Mercier JC, El Yaagoubi A, Nguyen- Huu L, Reeve HL, and Hampl V. Molecular identification of the role of voltage-gated K+ channels, Kv1.5 and Kv2.1, in hypoxic pulmonary vasoconstriction and control of resting membrane potential in rat pulmonary artery myocytes. J Clin Invest 101:2319–30, 1998.PubMedCrossRefGoogle Scholar
  7. 7.
    Archer SL, Weir EK, Reeve HL, and Michelakis E. Molecular identification of O2 sensors and O2-sensitive potassium channels in the pulmonary circulation. Adv Exp Med Biol 475:219–40,2000.PubMedGoogle Scholar
  8. 8.
    Barron JT, Gu L, and Parrillo JE. Cytoplasmic redox potential affects energetics and contractile reactivity of vascular smooth muscle. J Mol Cell Cardiol 29: 2225–32, 1997.PubMedCrossRefGoogle Scholar
  9. 9.
    Barron JT, Gu L, and Parrillo JE. Relation of NADH/NAD to contraction in vascular smooth muscle. Mol Cel lBiochem 194: 283–90, 1999.CrossRefGoogle Scholar
  10. 10.
    Bersin RM, and Stacpoole PW. Dichloroacetate as metabolic therapy for myocardial ischemia and failure. Am Heart J 134: 841–55,1997.PubMedCrossRefGoogle Scholar
  11. 11.
    Champion HC, Bivalacqua TJ, D’Souza FM, Ortiz LA, Jeter JR, Toyoda K, Heistad DD, Hyman AL, and Kadowitz PJ. Gene transfer of endothelial nitric oxide synthase to the lung of the mouse in vivo. Effect on agonist-induced and flow-mediated vascular responses. Circ Res 84: 1422–32, 1999.PubMedCrossRefGoogle Scholar
  12. 12.
    Champion HC, Bivalacqua TJ, Toyoda K, Heistad DD, Hyman AL, and Kadowitz PJ. In vivo gene transfer of prepro-calcitonin gene-related peptide to the lung attenuates chronic hypoxia-induced pulmonary hypertension in the mouse. Circulation 101: 923–30, 2000.PubMedCrossRefGoogle Scholar
  13. 13.
    Deng Z, Morse JH, Slager SL, Cuervo N, Moore KJ, Venetos G, Kalachikov S, Cayanis E, Fischer SG, Barst RJ, Hodge SE, and Knowles JA. Familial primary pulmonary hypertension (gene PPH1) is caused by mutations in the bone morphogenetic protein receptor-II gene. Am J Hum Genet 67: 737–44, 2000.PubMedCrossRefGoogle Scholar
  14. 14.
    Dresdale DT, Schultz M, and Mitchom RJ. Primary pulmonary hypertension. 1. Clinical and hemodynamic study. Am. J. Med. 11: 686–673, 1951.PubMedCrossRefGoogle Scholar
  15. 15.
    Grossman W, and Bairn D. Cardiac Cathterization, Angiography and Intervention. Malvern, PA: Lea & Febiger, 1991.Google Scholar
  16. 16.
    He TC, Zhou S, da Costa LT, Yu J, Kinzler KW, and Vogelstein B. A simplifed system for generating recombinant adenoviruses. Proc. Natl. Acad Sci USA. 95: 2509–2514, 1998.PubMedCrossRefGoogle Scholar
  17. 17.
    Levitan ES, Gealy R, Trimmer JS, and Takimoto K. Membrane depolarization inhibits Kv1.5 voltage-gated K+ channel gene transcription and protein expression in pituitary cells. J Biol Chem 270: 6036–41, 1995.PubMedCrossRefGoogle Scholar
  18. 18.
    Lewis JF, DaCosta M, Wargowich T, and Stacpoole P. Effects of dichloroacetate in patients with congestive heart failure. Clin Cardiol 21: 888–92, 1998.PubMedCrossRefGoogle Scholar
  19. 19.
    Michelakis E, Rebeyka I, Bateson J, Olley P, Puttagunta L, and Archer S. Voltage-gated potassium channels in human ductus arteriosus [letter]. Lancet 356: 134–7, 2000.PubMedCrossRefGoogle Scholar
  20. 20.
    Michelakis E, Weir EK, Wu XS, Nsair A, Waite R, Hashimoto K, and Archer S. Potassium channels regulate tone in rat pulmonary veins. Am J Physiol (Lung Cell Mol Physiol) in press, 2001.Google Scholar
  21. 21.
    Michelakis ED, Weir EK, Nelson DP, Reeve HL, Tolarova S, and Archer SL. Dexfenfluramine elevates systemic blood pressure by inhibiting potassium currents in vascular smooth muscle cells. J Pharmacol ExpTher 291: 1143–9, 1999.Google Scholar
  22. 22.
    Nelson MT, and Quayle JM. Physiological roles and properties of potassium channels in arterial smooth muscle. Am J Physiol 268: C799–822, 1995.PubMedGoogle Scholar
  23. 23.
    Platoshyn O, Golovina VA, Bailey CL, Limsuwan A, Krick S, Juhaszova M, Seiden JE, Rubin LJ, and Yuan JX. Sustained membrane depolarization and pulmonary artery smooth muscle cell proliferation [In Process Citation]. Am J Physiol Cell Physiol 279: C1540–9, 2000.PubMedGoogle Scholar
  24. 24.
    Reeve HL, Michelakis ED, Nelson D, Weir EK, and Archer SL. Chronic hypoxic pulmonary hypertension; evidence for dowregulation of a redox-based oxygen sensor. J Appl Physiol in press, 2001.Google Scholar
  25. 25.
    Reeve HL, Weir EK, Nelson DP, Peterson DA, and Archer SL. Opposing effects of oxidants and antioxidants on K+ channel activity and tone in rat vascular tissue. Exp Physiol 80: 825–34, 1995.PubMedGoogle Scholar
  26. 26.
    Romberg E. Lieber slerose der lungenarterien. Deutsch Arch Klin Med 48: 197, 1891.Google Scholar
  27. 27.
    Rozanski GJ, Xu Z, Zhang K, and Patel KP. Altered K+ current of ventricular myocytes in rats with chronic myocardial infarction. Am J Physiol 274: H259–65, 1998.PubMedGoogle Scholar
  28. 28.
    Smirnov SV, Robertson TP, Ward JP, and Aaronson PI. Chronic hypoxia is associated with reduced delayed rectifier K+ current in rat pulmonary artery muscle cells. Am J Physiol 266:H365–70, 1994.PubMedGoogle Scholar
  29. 29.
    Stacpoole PW. The pharmacology of dichloroacetate. Metabolism 38: 1124–44, 1989.PubMedCrossRefGoogle Scholar
  30. 30.
    Wang J, Juhaszova M, Conte JV, Jr., Gaine SP, Rubin LJ, and Yuan JX. Action of fenfluramine on voltage-gated K+ channels in human pulmonary- artery smooth- muscle cells [letter]. Lancet 352: 290, 1998.PubMedCrossRefGoogle Scholar
  31. 31.
    Wang J, Juhaszova M, Rubin LJ, and Yuan XJ. Hypoxia inhibits gene expression of voltage-gated K+ channel alpha subunits in pulmonary artery smooth muscle cells. J Clin Invest 100: 2347–53, 1997.PubMedCrossRefGoogle Scholar
  32. 32.
    Weir EK, Reeve HL, Huang JMC, Michelakis E, Nelson DP, Hampl V, and Archer SL. The anorexic agents, aminorex, fenfluramine, and dexfenfluramine inhibit potassium current in rat pulmonary vascular smooth muscle and cause pulmonary vasoconstriction. Circulation 94: 2216–2220, 1996.PubMedCrossRefGoogle Scholar
  33. 33.
    Weir EK, Reeve HL, Johnson G, Michelakis ED, Nelson DP, and Archer SL. A role for potassium channels in smooth muscle cells and platelets in the etiology of primary pulmonary hypertension. Chest 114: 200S–204S, 1998.PubMedCrossRefGoogle Scholar
  34. 34.
    Yuan JX, Aldinger AM, Juhaszova M, Wang J, Conte JV, Jr., Gaine SP, Orens JB, and Rubin LJ. Dysfunctional voltage-gated K+ channels in pulmonary artery smooth muscle cells of patients with primary pulmonary hypertension. Circulation 98: 1400–6, 1998.PubMedCrossRefGoogle Scholar

Copyright information

© Springer Science+Business Media New York 2001

Authors and Affiliations

  • Evangelos D. Michelakis
    • 1
  • Jason R. B. Dyck
    • 1
  • M. Sean McMurtry
    • 1
  • Shaohua Wang
    • 2
  • Xi-Chen Wu
    • 1
  • Rohit Moudgil
    • 1
  • Kyoko Hashimoto
    • 1
  • Lakshmi Puttagunta
    • 3
  • Stephen L. Archer
    • 1
    • 4
  1. 1.Department of Medicine (Cardiology) and the Vascular Biology GroupUniversity of AlbertaEdmontonCanada
  2. 2.Department of Surgery, Division of Cardiac SurgeryUniversity of AlbertaEdmontonCanada
  3. 3.Department of PathologyUniversity of AlbertaEdmontonCanada
  4. 4.Department of PhysiologyUniversity of AlbertaEdmontonCanada

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