Annals of Biomedical Engineering

, Volume 44, Issue 7, pp 2218–2227 | Cite as

Low Shear Stress Inhibited Endothelial Cell Autophagy Through TET2 Downregulation

  • Qin Yang
  • Xiaohong Li
  • Rongqing Li
  • Juan Peng
  • Zuo Wang
  • Zhisheng Jiang
  • Xiaoqing Tang
  • Zhao Peng
  • Yu Wang
  • Dangheng Wei


Low shear stress plays a crucial role in the initiation and progression of atherosclerotic lesions. However, the detailed mechanisms of these processes remain unclear. In this study, the effect of low shear stress on endothelial cell autophagy and its potential mechanism were investigated. Results showed autophagy dysfunction and ten-eleven translocation 2 (TET2) protein downregulation during atherosclerotic lesion progression. Autophagic markers BECLIN 1 and LC3II/LC3I under low shear stress (5 dyne/cm2) obviously decreased compared with those under physiological shear stress (15 dyne/cm2), whereas autophagic substrate p62 increased. TET2 expression was also downregulated under low shear stress. Endothelial cell autophagy was improved with TET2 overexpression but was impaired by TET2 siRNA treatment. Moreover, TET2 overexpression upregulated the expression of endothelial cell nitric oxide synthase (eNOS) and downregulated the expression of endothelin-1 (ET-1). TET2 siRNA further attenuated eNOS expression and stimulated ET-1 expression. Overall, the results showed that low shear stress downregulated endothelial cell autophagy by impaired TET2 expression, which might contribute to the atherogenic process.


Low shear stress Autophagy Ten-eleven translocation 2 protein Endothelial cell Atherosclerosis 



The present research is supported by the National Natural Science Foundation of China (81370378, 30800449), the construct program of the key discipline in Hunan province and Zhengxiang Scholar Program of University of South China (2014-004).


  1. 1.
    Bharath, L. P., R. Mueller, Y. Li, T. Ruan, D. Kunz, R. Goodrich, T. Mills, L. Deeter, and A. Sargsyan. Anandh Babu PV, Graham TE, Symons JD. Impairment of autophagy in endothelial cells prevents shear-stress-induced increases in nitric oxide bioavailability. Can J Physiol Pharmacol. 92(7):605–612, 2014.CrossRefPubMedGoogle Scholar
  2. 2.
    Chatzizisis, Y. S., A. U. Coskun, M. Jonas, E. R. Edelman, C. L. Feldman, and P. H. Stone. Role of endothelial shear stress in the natural history of coronary atherosclerosis and vascular remodeling: molecular, cellular, and vascular behavior. J. Am. Coll. Cardiol. 49(25):2379–2393, 2007.CrossRefPubMedGoogle Scholar
  3. 3.
    Chatzizisis, Y. S., M. Jonas, A. U. Coskun, R. Beigel, B. V. Stone, C. Maynard, R. G. Gerrity, W. Daley, C. Rogers, E. R. Edelman, C. L. Feldman, and P. H. Stone. Prediction of the localization of high-risk coronary atherosclerotic plaques on the basis of lowendothelial shear stress: an intravascular ultrasound and histopathology natural history study. Circulation 117(8):993–1002, 2008.CrossRefPubMedGoogle Scholar
  4. 4.
    Dawlaty, M. M., A. Breiling, T. Le, M. I. Barrasa, G. Raddatz, Q. Gao, B. E. Powell, A. W. Cheng, K. F. Faull, F. Lyko, and R. Jaenisch. Loss of Tet enzymes compromises proper differentiation of embryonic stem cells. Dev Cell. 29(1):102–111, 2014.CrossRefPubMedPubMedCentralGoogle Scholar
  5. 5.
    De Meyer, G. R., M. O. Grootaert, C. F. Michiels, A. Kurdi, D. M. Schrijvers, and W. Martinet. Autophagy in vascular disease. Circ. Res. 116(3):468–479, 2015.CrossRefPubMedGoogle Scholar
  6. 6.
    Feng, J., N. Shao, K. E. Szulwach, V. Vialou, J. Huynh, C. Zhong, T. Le, D. Ferguson, M. E. Cahill, Y. Li, J. W. Koo, E. Ribeiro, B. Labonte, B. M. Laitman, D. Estey, V. Stockman, P. Kennedy, T. Couroussé, I. Mensah, G. Turecki, K. F. Faull, G. L. Ming, H. Song, G. Fan, P. Casaccia, L. Shen, P. Jin, and E. J. Nestler. Role of Tet1 and 5-hydroxymethylcytosine in cocaine action. Nat. Neurosci. 18(4):536–544, 2015.CrossRefPubMedPubMedCentralGoogle Scholar
  7. 7.
    Green, J., A. Yurdagul, Jr, M. C. McInnis, P. Albert, and A. W. Orr. Flow patterns regulate hyperglycemia-induced subendothelial matrix remodeling during early atherogenesis. Atherosclerosis. 232(2):277–284, 2014.CrossRefPubMedPubMedCentralGoogle Scholar
  8. 8.
    Grimmel, M., C. Backhaus, and T. Proikas-Cezanne. WIPI-mediated autophagy and longevity. Cells. 4(2):202–217, 2015.CrossRefPubMedPubMedCentralGoogle Scholar
  9. 9.
    Guo, F., X. Li, J. Peng, Y. Tang, Q. Yang, L. Liu, Z. Wang, Z. Jiang, M. Xiao, C. Ni, R. Chen, D. Wei, and G. X. Wang. Autophagy regulates vascular endothelial cell eNOS and ET-1 expression induced by laminar shearstress in an ex vivo perfused system. Ann. Biomed. Eng. 42(9):1978–1988, 2014.CrossRefPubMedGoogle Scholar
  10. 10.
    Harvald, E. B., A. S. Olsen, and N. J. Færgeman. Autophagy in the light of sphingolipid metabolism. Apoptosis 20(5):658–670, 2015.CrossRefPubMedPubMedCentralGoogle Scholar
  11. 11.
    Hon, G. C., C. X. Song, T. Du, F. Jin, S. Selvaraj, A. Y. Lee, C. A. Yen, Z. Ye, S. Q. Mao, B. A. Wang, S. Kuan, L. E. Edsall, B. S. Zhao, G. L. Xu, C. He, and B. Ren. 5mC oxidation by Tet2 modulates enhancer activity and timing of transcriptome reprogramming during differentiation. Mol Cell. 56(2):286–297, 2014.CrossRefPubMedPubMedCentralGoogle Scholar
  12. 12.
    Kim, K. H., and M. S. Lee. Autophagy—a key player in cellular and body metabolism. Nat Rev Endocrinol. 10(6):322–337, 2014.CrossRefPubMedGoogle Scholar
  13. 13.
    Ko, M., J. An, W. A. Pastor, S. B. Koralov, K. Rajewsky, and A. Rao. TET proteins and 5-methylcytosine oxidation in hematological cancers. Immunol. Rev. 263(1):6–21, 2015.CrossRefPubMedPubMedCentralGoogle Scholar
  14. 14.
    Koskinas, K. C., C. L. Feldman, Y. S. Chatzizisis, A. U. Coskun, M. Jonas, C. Maynard, A. B. Baker, M. I. Papafaklis, E. R. Edelman, and P. H. Stone. Natural history of experimental coronary atherosclerosis and vascular remodeling in relation to endothelial shear stress: a serial, in vivo intravascular ultrasound study. Circulation 121(19):2092–2101, 2010.CrossRefPubMedPubMedCentralGoogle Scholar
  15. 15.
    Koskinas, K. C., G. K. Sukhova, A. B. Baker, M. I. Papafaklis, Y. S. Chatzizisis, A. U. Coskun, T. Quillard, M. Jonas, C. Maynard, A. P. Antoniadis, G. P. Shi, P. Libby, E. R. Edelman, C. L. Feldman, and P. H. Stone. Thin-capped atheromata with reduced collagen content in pigs develop in coronary arterial regions exposed to persistently low endothelial shear stress. Arterioscler. Thromb. Vasc. Biol. 33(7):1494–1504, 2013.CrossRefPubMedPubMedCentralGoogle Scholar
  16. 16.
    Lavandero, S., M. Chiong, B. A. Rothermel, and J. A. Hill. Autophagy in cardiovascular biology. J. Clin. Invest. 125(1):55–64, 2015.CrossRefPubMedPubMedCentralGoogle Scholar
  17. 17.
    Li, G., J. Peng, Y. Liu, X. Li, Q. Yang, Y. Li, Z. Tang, Z. Wang, Z. Jiang, and D. Wei. Oxidized low-density lipoprotein inhibits HP-1-derived macrophage autophagy via TET2 down-regulation. Lipids 50(2):177–183, 2015.CrossRefPubMedGoogle Scholar
  18. 18.
    Li, X., Q. Yang, Z. Wang, and D. Wei. Shear stress in atherosclerotic plaque determination. DNA Cell Biol. 33(12):830–838, 2014.CrossRefPubMedGoogle Scholar
  19. 19.
    Liu, R., Y. Jin, W. H. Tang, L. Qin, X. Zhang, G. Tellides, J. Hwa, J. Yu, and K. A. Martin. Ten-eleven translocation-2 (TET2) is a master regulator of smooth muscle cell plasticity. Circulation 128(18):2047–2057, 2013.CrossRefPubMedPubMedCentralGoogle Scholar
  20. 20.
    Madeo, F., A. Zimmermann, M. C. Maiuri, and G. Kroemer. Essential role for autophagy in life span extension. J. Clin. Invest. 125(1):85–93, 2015.CrossRefPubMedPubMedCentralGoogle Scholar
  21. 21.
    Magné, J., P. Gustafsson, H. Jin, L. Maegdefessel, K. Hultenby, A. Wernerson, P. Eriksson, A. Franco-Cereceda, P. T. Kovanen, I. Gonçalves, and E. Ehrenborg. ATG16L1 expression in carotid atherosclerotic plaques is associated with plaque vulnerability. Arterioscler. Thromb. Vasc. Biol. 35(5):1226–1235, 2015.CrossRefPubMedGoogle Scholar
  22. 22.
    Nah, J., J. Yuan, and Y. K. Jung. Autophagy in neurodegenerative diseases: from mechanism to therapeutic approach. Mol. Cells 38(5):381–389, 2015.CrossRefPubMedPubMedCentralGoogle Scholar
  23. 23.
    Nakajima, H., and H. Kunimoto. TET2 as an epigenetic master regulator for normal and malignant hematopoiesis. Cancer Sci. 105(9):1093–1099, 2014.CrossRefPubMedPubMedCentralGoogle Scholar
  24. 24.
    Nussenzweig, S. C., S. Verma, and T. Finkel. The role of autophagy in vascular biology. Circ. Res. 116(3):480–488, 2015.CrossRefPubMedPubMedCentralGoogle Scholar
  25. 25.
    Okashita, N., Y. Kumaki, K. Ebi, M. Nishi, Y. Okamoto, M. Nakayama, S. Hashimoto, T. Nakamura, K. Sugasawa, N. Kojima, T. Takada, M. Okano, and Y. Seki. PRDM14 promotes active DNA demethylation through the ten-eleven translocation (TET)-mediated base excision repair pathway in embryonic stem cells. Development. 141(2):269–280, 2014.CrossRefPubMedGoogle Scholar
  26. 26.
    Peng, N., N. Meng, S. Wang, F. Zhao, J. Zhao, L. Su, S. Zhang, Y. Zhang, B. Zhao, and J. Miao. An activator of mTOR inhibits oxLDL-induced autophagy and apoptosis in vascular endothelial cells and restricts atherosclerosis in apolipoprotein E−/− mice. Sci Rep. 4:5519, 2014.PubMedPubMedCentralGoogle Scholar
  27. 27.
    Petersen, M., D. Hofius, and S. U. Andersen. Signaling unmasked: autophagy and catalase promote programmed cell death. Autophagy. 10(3):520–521, 2014.CrossRefPubMedPubMedCentralGoogle Scholar
  28. 28.
    Qi, Y. X., J. Jiang, X. H. Jiang, X. D. Wang, S. Y. Ji, Y. Han, D. K. Long, B. R. Shen, Z. Q. Yan, S. Chien, and Z. L. Jiang. PDGF-BB and TGF-{beta}1 on cross-talk etween endothelial and smooth muscle cells in vascular remodeling induced by low shear stress. Proc. Natl. Acad. Sci. USA 108(5):1908–1913, 2011.CrossRefPubMedPubMedCentralGoogle Scholar
  29. 29.
    Rasmussen, K. D., G. Jia, J. V. Johansen, M. T. Pedersen, N. Rapin, F. O. Bagger, B. T. Porse, O. A. Bernard, J. Christensen, and K. Helin. Loss of TET2 in hematopoietic cells leads to DNA hypermethylation of active enhancers and induction of leukemogenesis. Genes Dev. 29(9):910–922, 2015.CrossRefPubMedPubMedCentralGoogle Scholar
  30. 30.
    Razani, B., C. Fangs, T. Coleman, R. Emanuel, H. Wen, S. Hwang, J. P. Ting, H. W. Virgin, M. B. Kastan, and C. F. Semenkovich. Autophagy links inflammasomes to atherosclerotic progression. Cell Metab. 15(4):534–544, 2012.CrossRefPubMedPubMedCentralGoogle Scholar
  31. 31.
    Robertson, A. B., J. A. Dahl, and A. Klungland. DNA metabolism: bases of DNA repair and regulation. Nat. Chem. Biol. 10(7):487–488, 2014.CrossRefPubMedGoogle Scholar
  32. 32.
    Santiago, M., C. Antunes, M. Guedes, and N. Sousa. Marques CJ.TET enzymes and DNA hydroxymethylation in neural development and function - how critical are they? Genomics 104(5):334–340, 2014.CrossRefPubMedGoogle Scholar
  33. 33.
    Stone, P. H., S. Saito, S. Takahashi, Y. Makita, S. Nakamura, T. Kawasaki, A. Takahashi, T. Katsuki, S. Nakamura, A. Namiki, A. Hirohata, T. Matsumura, S. Yamazaki, H. Yokoi, S. Tanaka, S. Otsuji, F. Yoshimachi, J. Honye, D. Harwood, M. Reitman, A. U. Coskun, M. I. Papafaklis, and C. L. Feldman. Prediction of progression of coronary artery disease and clinical outcomes using vascular profiling of endothelial shear stress and arterial plaque characteristics: the prediction study. Circulation 126(2):172–181, 2012.CrossRefPubMedGoogle Scholar
  34. 34.
    Xiong, Y., G. Yepuri, M. Forbiteh, Y. Yu, J. P. Montani, Z. Yang, and X. F. Ming. ARG2 impairs endothelial autophagy through regulation of MTOR and PRKAA/AMPK signaling in advanced atherosclerosis. Autophagy. 10(12):2223–2238, 2014.CrossRefPubMedPubMedCentralGoogle Scholar
  35. 35.
    Young, A., W. Wu, W. Sun, H. Benjamin Larman, N. Wang, Y. S. Li, J. Y. Shyy, S. Chien, and G. García-Cardeña. Flow activation of AMP-activated protein kinase in vascular endothelium leads to Krüppel-like factor 2 expression. Arterioscler Thromb Vasc Biol. 29(11):1902–1908, 2009.CrossRefPubMedPubMedCentralGoogle Scholar
  36. 36.
    Zhou, J., Y. S. Li, and S. Chien. Shear stress-initiated signaling and its regulation of endothelial function. Arterioscler. Thromb. Vasc. Biol. 34(10):2191–2198, 2014.CrossRefPubMedPubMedCentralGoogle Scholar

Copyright information

© Biomedical Engineering Society 2015

Authors and Affiliations

  1. 1.Institute of Cardiovascular Disease, Key Laboratory for Atherosclerology of Hunan ProvinceUniversity of South ChinaHengyangPeople’s Republic of China
  2. 2.Affiliated Hospital Xiang Nan UniversityChengzhouPeople’s Republic of China
  3. 3.Department of Neurosurgery, Tongji Hospital, Tongji Medical CollegeHuazhong University of Science and TechnologyWuhanPeople’s Republic of China
  4. 4.Department of Physiology & Institute of Neuroscience, Medical SchoolUniversity of South ChinaHengyangPeople’s Republic of China

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