World J Cardiol. 2015 Jun 26;7(6):331-43. doi: 10.4330/wjc.v7.i6.331.

Bone morphogenetic protein-4 and transforming growth factor-beta1 mechanisms in acute valvular response to supra-physiologic hemodynamic stresses.

World journal of cardiology

Ling Sun, Philippe Sucosky

PMID: 26131338 PMCID: PMC4478568 DOI: 10.4330/wjc.v7.i6.331

Abstract

AIM: To explore ex vivo the role of bone morphogenetic protein-4 (BMP-4) and transforming growth factor-beta1 (TGF-β1) in acute valvular response to fluid shear stress (FSS) abnormalities.

METHODS: Porcine valve leaflets were subjected ex vivo to physiologic FSS, supra-physiologic FSS magnitude at normal frequency and supra-physiologic FSS frequency at normal magnitude for 48 h in a double-sided cone-and-plate bioreactor filled with standard culture medium. The role of BMP-4 and TGF-β1 in the valvular response was investigated by promoting or inhibiting the downstream action of those cytokines via culture medium supplementation with BMP-4 or the BMP antagonist noggin, and TGF-β1 or the TGF-β1 inhibitor SB-431542, respectively. Fresh porcine leaflets were used as controls. Each experimental group consisted of six leaflet samples. Immunostaining and immunoblotting were performed to assess endothelial activation in terms of intercellular adhesion molecule-1 and vascular cell adhesion molecule-1 expressions, paracrine signaling in terms of BMP-4 and TGF-β1 expressions and extracellular matrix (ECM) remodeling in terms of cathepsin L, cathepsin S, metalloproteinases (MMP)-2 and MMP-9 expressions. Immunostained images were quantified by normalizing the intensities of positively stained regions by the number of cells in each image while immunoblots were quantified by densitometry.

RESULTS: Regardless of the culture medium, physiologic FSS maintained valvular homeostasis. Tissue exposure to supra-physiologic FSS magnitude in standard medium stimulated paracrine signaling (TGF-β1: 467% ± 22% vs 100% ± 6% in fresh controls, BMP-4: 258% ± 22% vs 100% ± 4% in fresh controls; P < 0.05) and ECM degradation (MMP-2: 941% ± 90% vs 100% ± 19% in fresh controls, MMP-9: 1219% ± 190% vs 100% ± 16% in fresh controls, cathepsin L: 1187% ± 175% vs 100% ± 12% in fresh controls, cathepsin S: 603% ± 88% vs 100% ± 13% in fresh controls; P < 0.05), while BMP-4 supplementation also promoted fibrosa activation and TGF-β1 inhibition reduced MMP-9 expression to the native tissue level (MMP-9: 308% ± 153% with TGF-β1 inhibition vs 100% ± 16% in fresh control; P > 0.05). Supra-physiologic FSS frequency had no effect on endothelial activation and paracrine signaling regardless of the culture medium but TGF-β1 silencing attenuated FSS-induced ECM degradation via MMP-9 downregulation (MMP-9: 302% ± 182% vs 100% ± 42% in fresh controls; P > 0.05).

CONCLUSION: Valvular tissue is sensitive to FSS abnormalities. The TGF-β1 inhibitor SB-431542 is a potential candidate molecule for attenuating the effects of FSS abnormalities on valvular remodeling.

Keywords: Aortic valve; Bone morphogenetic protein; Calcification; Fluid shear stress; Transforming growth factor beta

References

1. J Am Coll Cardiol. 1994 Apr;23(5):1162-70 - PubMed
2. Blood Press. 2005;14(5):264-72 - PubMed
3. Am J Physiol Heart Circ Physiol. 2012 Sep 15;303(6):H721-31 - PubMed
4. Mol Pharmacol. 2002 Jul;62(1):65-74 - PubMed
5. J Am Coll Cardiol. 2009 Apr 21;53(16):1456-8 - PubMed
6. Arterioscler Thromb Vasc Biol. 2009 Feb;29(2):254-60 - PubMed
7. PLoS One. 2012;7(10):e48843 - PubMed
8. J Biomech. 2010 Jan 5;43(1):87-92 - PubMed
9. Biomech Model Mechanobiol. 2012 Sep;11(7):1085-96 - PubMed
10. Ann Thorac Surg. 2007 Mar;83(3):946-53 - PubMed
11. Circulation. 2001 Mar 20;103(11):1522-8 - PubMed
12. Circulation. 2003 May 6;107(17 ):2181-4 - PubMed
13. Circulation. 2007 Jan 23;115(3):377-86 - PubMed
14. J Biomech Eng. 2014 Apr;136(4):null - PubMed
15. PLoS One. 2013 Dec 23;8(12):e84433 - PubMed
16. Ann Biomed Eng. 2006 Nov;34(11):1655-65 - PubMed
17. Age Ageing. 2004 Nov;33(6):538-44 - PubMed
18. Cardiovasc Pathol. 2011 Nov-Dec;20(6):334-42 - PubMed
19. Nature. 2005 Sep 8;437(7056):270-4 - PubMed
20. J Am Coll Cardiol. 1997 Mar 1;29(3):630-4 - PubMed
21. Circulation. 1994 Aug;90(2):844-53 - PubMed
22. Mol Pharmacol. 2002 Jul;62(1):58-64 - PubMed
23. J Heart Valve Dis. 2006 Sep;15(5):622-9 - PubMed
24. Nature. 2002 Dec 12;420(6916):636-42 - PubMed
25. Biochem Biophys Res Commun. 2002 Aug 16;296(2):267-73 - PubMed
26. Circulation. 2005 Feb 22;111(7):920-5 - PubMed
27. Am J Pathol. 2010 Jul;177(1):49-57 - PubMed
28. J Biomech Eng. 2008 Jun;130(3):035001 - PubMed
29. Heart. 2000 Jan;83(1):81-5 - PubMed
30. Rev Endocr Metab Disord. 2006 Jun;7(1-2):51-65 - PubMed
31. J Heart Valve Dis. 2011 Jul;20(4):449-63 - PubMed
32. Ann Thorac Surg. 2003 Feb;75(2):457-65; discussion 465-6 - PubMed
33. Arterioscler Thromb Vasc Biol. 2010 Dec;30(12 ):2482-6 - PubMed
34. J Heart Valve Dis. 2008 Jan;17(1):62-73 - PubMed
35. Cell. 1996 Aug 23;86(4):599-606 - PubMed
36. Ann Biomed Eng. 2011 Aug;39(8):2174-85 - PubMed
37. Ann Thorac Surg. 2002 Apr;73(4):1346-54 - PubMed
38. J Am Coll Cardiol. 2014 Jun 10;63(22):2438-88 - PubMed
39. Cardiovasc Pathol. 2000 Sep-Oct;9(5):281-6 - PubMed

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