Pulmonary Medicine

Pulmonary Medicine / 2014 / Article

Letter to the Editor | Open Access

Volume 2014 |Article ID 725317 | 2 pages | https://doi.org/10.1155/2014/725317

Oscillatory Shear Stress-Induced Arginase Activity May Explain Reduced Exhaled Nitric Oxide Levels after Vest Chest Physiotherapy in Cystic Fibrosis

Academic Editor: Charlie Strange
Received07 Feb 2014
Accepted24 Feb 2014
Published03 Apr 2014

The well-executed study by Sisson et al. [1] demonstrates the potential of vest chest physiotherapy (VCPT) in improving airway clearance in cystic fibrosis (CF) patients. The authors point out that they observed a nonsignificant tendency towards higher exhaled nitric oxide () levels in CF compared to healthy control subjects which is at odds with previous findings of lower in CF [2, 3]. Contrary to Sisson et al.’s hypothesis, VCPT in CF patients reduced rather than increased . The authors discuss this unexpected finding with regard to increased cellular NO utilisation and distal airway mucous barriers to NO diffusion.

An alternative explanation involves NO synthetase (NOS) and arginase activity in airway epithelial cells. Both enzymes compete for L-arginine as substrate and imbalances in activity levels are believed to be important in the pathogenesis of airway inflammation and hyperreactivity [4]. Arginase converts L-arginine into L-ornithine and urea, effectively modulating NOS activity, proinflammatory oxidant species generation, and airway remodelling [5]. Impaired lung function in CF is likely associated with reduced NO-mediated bronchodilation arising from low levels of L-arginine, impaired NOS expression, and increased arginase activity [6, 7]. Elevated systemic arginase and concomitantly reduced L-arginine levels were observed in acutely hospitalised CF patients and normalised after successful treatment [8]. Increased arginase activity, in addition to limiting NO production, also contributes to CF lung pathology through downstream products [9], is associated with Pseudomonas infection, and inversely related to lung function [10]. Arginase is moreover thought to play a role in the pathogenesis of other lung diseases like asthma and chronic obstructive pulmonary diseases [11, 12]. Recently, inhaled L-arginine was demonstrated to be a safe and potentially beneficial treatment approach in CF [13].

A possible mechanism to explain Sisson et al.’s [1] surprising finding of lower after VCPT may be an increase in arginase activity through oscillatory mechanical stimulation of lung epithelial cells. Several studies in animal and cell models have demonstrated that specific patterns of mechanical stimulation can induce vascular endothelial arginase expression and activity. For instance, oscillatory shear stress induced stronger arginase activation than application of unidirectional shear force in porcine [14] and ApoE-deficient murine carotid artery segments [15]. An in vitro study showed that cyclic stretching of vascular smooth muscle cells upregulated arginase mRNA expression and enzyme activity whilst inhibiting NOS [16]. The VCPT device used in Sisson et al.’s [1] study produced oscillatory inflation/deflation cycles at a rate of 10–15 Hz throughout 20-minute treatment sessions. Thus, a possible explanation for reduced exhaled NO could be oscillatory shear stress-induced upregulation of arginase activity and associated inhibition of NOS. Whilst the observed vascular endothelial response in arginase activity to shear forces remains to be demonstrated for airway epithelial cells, the suggested link provides a plausible theory to account for Sisson et al.’s intriguing findings.

Conflict of Interests

The author declares that there is no conflict of interests regarding the publication of this paper.

References

  1. J. H. Sisson, T. A. Wyatt, J. A. Pavlik, P. S. Sarna, and P. J. Purphy, “Vest chest physiotherapy airway clearance is associated with nitric oxide metabolism,” Pulmonary Medicine, vol. 2013, Article ID 291375, 6 pages, 2013. View at: Publisher Site | Google Scholar
  2. P. J. Barnes, R. A. Dweik, A. F. Gelb et al., “Exhaled nitric oxide in pulmonary diseases a comprehensive review,” Chest, vol. 138, no. 3, pp. 682–692, 2010. View at: Publisher Site | Google Scholar
  3. M. Högman, “Extended NO analysis in health and disease,” Journal of Breath Research, vol. 6, no. 4, Article ID 047103, 2010. View at: Google Scholar
  4. A. Strapkova and M. Antosova, “Competition of NO synthases and arginase in the airways hyperreactivity,” General Physiology and Biophysics, vol. 30, no. 1, pp. 75–83, 2011. View at: Publisher Site | Google Scholar
  5. R. C. Benson, K. A. Hardy, and C. R. Morris, “Arginase and arginine dysregulation in asthma,” Journal of Allergy, vol. 2011, Article ID 736319, 12 pages, 2011. View at: Publisher Site | Google Scholar
  6. H. Grasemann and F. Ratjen, “Nitric oxide and l-arginine deficiency in cystic fibrosis,” Current Pharmaceutical Design, vol. 18, no. 5, pp. 726–736, 2012. View at: Publisher Site | Google Scholar
  7. H. Grasemann, R. Schwiertz, S. Matthiesen, K. Racké, and F. Ratjen, “Increased arginase activity in cystic fibrosis airways,” The American Journal of Respiratory and Critical Care Medicine, vol. 172, no. 12, pp. 1523–1528, 2005. View at: Publisher Site | Google Scholar
  8. H. Grasemann, R. Schwiertz, C. Grasemann, U. Vester, K. Racké, and F. Ratjen, “Decreased systemic bioavailability of L-arginine in patients with cystic fibrosis,” Respiratory Research, vol. 7, article 87, 2006. View at: Publisher Site | Google Scholar
  9. H. Grasemann, D. Shehnaz, M. Enomoto, M. Leadley, J. Belik, and F. Ratjen, “L-ornithine derived polyamines in cystic fibrosis airways,” PLoS ONE, vol. 7, no. 10, Article ID e46618, 2012. View at: Google Scholar
  10. B. S. Murphy, H. M. Bush, V. Sundareshan et al., “Characterization of macrophage activation states in patients with cystic fibrosis,” Journal of Cystic Fibrosis, vol. 9, no. 5, pp. 314–322, 2010. View at: Publisher Site | Google Scholar
  11. H. Maarsingh, T. Pera, and H. Meurs, “Arginase and pulmonary diseases,” Naunyn-Schmiedeberg's Archives of Pharmacology, vol. 378, no. 2, pp. 171–184, 2008. View at: Publisher Site | Google Scholar
  12. J.-M. Tadié, P. Henno, I. Leroy et al., “Role of nitric oxide synthase/arginase balance in bronchial reactivity in patients with chronic obstructive pulmonary disease,” The American Journal of Physiology: Lung Cellular and Molecular Physiology, vol. 294, no. 3, pp. L489–L497, 2008. View at: Publisher Site | Google Scholar
  13. H. Grasemann, E. Tullis, and F. Ratjen, “A randomized controlled trial on inhaled L-arginine in patients with cystic fibrosis,” Journal of Cystic Fibrosis, vol. 12, no. 5, pp. 468–474, 2013. View at: Google Scholar
  14. T. N. Thacher, V. Gambillara, F. Riche, P. Silacci, N. Stergiopulos, and R. F. da Silva, “Regulation of arginase pathway in response to wall shear stress,” Atherosclerosis, vol. 210, no. 1, pp. 63–70, 2010. View at: Publisher Site | Google Scholar
  15. V. C. Olivon, R. A. Fraga-Silva, D. Segers et al., “Arginase inhibition prevents the low shear stress-induced development of vulnerable atherosclerotic plaques in ApoE-/- mice,” Atherosclerosis, vol. 227, no. 2, pp. 236–243, 2013. View at: Google Scholar
  16. W. Durante, L. Liao, S. V. Reyna, K. J. Peyton, and A. I. Schafer, “Physiological cyclic stretch directs L-arginine transport and metabolism to collagen synthesis in vascular smooth muscle,” The FASEB Journal, vol. 14, no. 12, pp. 1775–1783, 2000. View at: Google Scholar

Copyright © 2014 Christoph Nowak. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


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