Skip to main content
Log in

Oxidized Low-Density Lipoprotein Inhibits THP-1-Derived Macrophage Autophagy via TET2 Down-regulation

  • Original Article
  • Published:
Lipids

Abstract

Oxidized low-density lipoprotein (ox-LDL) is an independent risk factor of atherosclerosis. However, the mechanism underlying its pro-atherosclerosis roles has not yet been well explored. DNA demethylation modification, via DNA methyltransferases or ten-eleven-translocation (TET) family, is a crisis epigenetic regulation for various biological and pathological processes. This study aimed to investigate the effects of ox-LDL on macrophage autophagy and its potential epigenetic mechanism. Results showed that after treatment with 0, 10, 20, 40 or 80 mg/L ox-LDL for 24 h, the autophagy markers Beclin 1 and LC3 expression were obviously decreased at protein levels (P < 0.05). The mRNA and protein expression of TET2 was evidently decreased (P < 0.05). After pre-treatment with TET2 siRNA, the mRNA and protein levels of Beclin 1 and LC3 decreased compared with the 80 mg/L treatment group (P < 0.01). The mRNA and protein levels of Beclin 1 and LC3-II were up-regulated (P < 0.05) in the 5-aza-2′-deoxycytidine (a DNA methyltransferase inhibitor) of pretreatment group. Consistent with the Western blot results, cell immunofluorescence showed that the protein concentration of LC3-II decreased in the TET2 siRNA group and increased in the 5-aza-2′-deoxycytidine group. Taken together, these results showed that DNA demethylation modifications regulate ox-LDL-treated THP-1 macrophages autophagy and TET2 might be a novel regulator.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Fig. 1
Fig. 2
Fig. 3
Fig. 4

Similar content being viewed by others

Abbreviations

ox-LDL:

Oxidized low-density lipoprotein

ATG5:

Autophagy-related gene 5

5hmC:

5-Hydroxymethylcytosine

TET:

Ten-eleven translocation

Azad:

5-Aza-2′-deoxycytidine

BSA:

Bovine serum albumin

LC3:

Microtubule-associated protein 1 light chain 3

PMA:

Phorbol-12-myristate-13-acetate

References

  1. Liao X, Sluimer JC, Wang Y, Subramanian M, Brown K, Pattison JS, Robbins J, Martinez J, Tabas I (2012) Macrophage autophagy plays a protective role in advanced atherosclerosis. Cell Metab 15(4):545–553

    Article  CAS  PubMed Central  PubMed  Google Scholar 

  2. Razani B, Feng C, Coleman T, Emanuel R, Wen H, Hwang S, Ting JP, Virgin HW, Kastan MB, Semenkovich CF (2012) Autophagy links inflammasomes to atherosclerotic progression. Cell Metab 15(4):534–544

    Article  CAS  PubMed Central  PubMed  Google Scholar 

  3. Kim KH, Lee MS (2014) Autophagy—a key player in cellular and body metabolism. Nat Rev Endocrinol 10(6):322–337

    Article  CAS  PubMed  Google Scholar 

  4. Lavandero S, Troncoso R, Rothermel BA, Martinet W, Sadoshima J, Hill JA (2013) Cardiovascular autophagy: concepts, controversies, and perspectives. Autophagy 9(10):1455–1466

    Article  CAS  PubMed  Google Scholar 

  5. Eisenberg T, Schroeder S, Büttner S, Carmona-Gutierrez D, Pendl T, Andryushkova A, Mariño G, Pietrocola F, Harger A, Zimmermann A, Magnes C, Sinner F, Sedej S, Pieber TR, Dengjel J, Sigrist S, Kroemer G, Madeo F (2014) A histone point mutation that switches on autophagy. Autophagy 10(6):1143–1145

    Article  PubMed  Google Scholar 

  6. Füllgrabe J, Klionsky DJ, Joseph B (2014) The return of the nucleus: transcriptional and epigenetic control of autophagy. Nat Rev Mol Cell Biol 15(1):65–74

    Article  PubMed  Google Scholar 

  7. Jiang YZ, Jiménez JM, Ou K, McCormick ME, Zhang LD, Davies PF (2014) Hemodynamic disturbed flow induces differential DNA methylation of endothelial Krüppel-like factor 4 promoter in vitro and in vivo. Circ Res 115(1):32–43

    Article  CAS  PubMed  Google Scholar 

  8. Borghini A, Cervelli T, Galli A, Andreassi MG (2013) DNA modifications in atherosclerosis: from the past to the future. Atherosclerosis 230(2):202–209

    Article  CAS  PubMed  Google Scholar 

  9. Yang XL, Tian J, Liang Y, Ma CJ, Yang AN, Wang J, Ma SC, Cheng Y, Hua X, Jiang YD (2014) Homocysteine induces blood vessel global hypomethylation mediated by LOX-1. Genet Mol Res 13(2):3787–3799

    Article  CAS  PubMed  Google Scholar 

  10. Huang YS, Zhi YF, Wang SR (2009) Hypermethylation of estrogen receptor-alpha gene in atheromatosis patients and its correlation with homocysteine. Pathophysiology 16(4):259–265

    Article  CAS  PubMed  Google Scholar 

  11. Wu H, Zhang Y (2014) Reversing DNA methylation: mechanisms, genomics, and biological functions. Cell 156(1–2):45–68

    Article  CAS  PubMed Central  PubMed  Google Scholar 

  12. Ito S, Shen L, Dai Q, Wu SC, Collins LB, Swenberg JA, He C, Zhang Y (2011) Tet proteins can convert 5-methylcytosine to 5-formylcytosine and 5-carboxylcytosine. Science 333(6047):1300–1303

    Article  CAS  PubMed Central  PubMed  Google Scholar 

  13. Ding Z, Wang X, Schnackenberg L, Khaidakov M, Liu S, Singla S, Dai Y, Mehta JL (2013) Regulation of autophagy and apoptosis in response to ox-LDL in vascular smooth muscle cells, and the modulatory effects of the microRNA hsa-let-7 g. Int J Cardiol 168(2):1378–1385

    Article  PubMed  Google Scholar 

  14. Mahmood DF, Jguirim-Souissi I, Khadija el-H, Blondeau N, Diderot V, Amrani S, Slimane MN, Syrovets T, Simmet T, Rouis M (2011) Peroxisome proliferator-activated receptor gamma induces apoptosis and inhibits autophagy of human monocyte-derived macrophages via induction of cathepsin L: potential role in atherosclerosis. J Biol Chem 286(33):28858–28866

    Article  CAS  PubMed Central  PubMed  Google Scholar 

  15. Ma J, Wan J, Meng J, Banerjee S, Ramakrishnan S, Roy S (2014) Methamphetamine induces autophagy as a pro-survival response against apoptotic endothelial cell death through the Kappa opioid receptor. Cell Death Dis 5:e1099

    Article  CAS  PubMed Central  PubMed  Google Scholar 

  16. Konishi A, Arakawa S, Yue Z, Shimizu S (2012) Involvement of Beclin 1 in engulfment of apoptotic cells. J Biol Chem 287(17):13919–13929

    Article  CAS  PubMed Central  PubMed  Google Scholar 

  17. Martinet W, De Meyer GR (2009) Autophagy in atherosclerosis: a cell survival and death phenomenon with therapeutic potential. Circ Res 104(3):304–317

    Article  CAS  PubMed  Google Scholar 

  18. Ouimet M, Franklin V, Mak E, Liao X, Tabas I, Marcel YL (2011) Autophagy regulates cholesterol efflux from macrophage foam cells via lysosomal acid lipase. Cell Metab 13(6):655–6567

    Article  CAS  PubMed Central  PubMed  Google Scholar 

  19. Wang X, Li L, Niu X, Dang X, Li P, Qu L, Bi X, Gao Y, Hu Y, Li M, Qiao W, Peng Z, Pan L (2014) mTOR enhances foam cell formation by suppressing the autophagy pathway. DNA Cell Biol 33(4):198–204

    Article  PubMed  Google Scholar 

  20. Bai H, Inoue J, Kawano T, Inazawa J (2012) A transcriptional variant of the LC3A gene is involved in autophagy and frequently inactivated in human cancers. Oncogene 31(40):4397–4408

    Article  CAS  PubMed  Google Scholar 

  21. Li Z, Chen B, Wu Y, Jin F, Xia Y, Liu X (2010) Genetic and epigenetic silencing of the beclin 1 gene in sporadic breast tumors. BMC Cancer 10:98

    Article  PubMed Central  PubMed  Google Scholar 

  22. Zhai C, Cheng J, Mujahid H, Wang H, Kong J, Yin Y, Li J, Zhang Y, Ji X, Chen W (2014) Selective inhibition of PI3K/Akt/mTOR signaling pathway regulates autophagy of macrophage and vulnerability of atherosclerotic plaque. PLoS One 9(3):e90563

    Article  PubMed Central  PubMed  Google Scholar 

  23. Williams-Bey Y, Boularan C, Vural A, Huang NN, Hwang IY, Shan-Shi C, Kehrl JH (2014) Omega-3 free fatty acids suppress macrophage inflammasome activation by inhibiting NF-κB activation and enhancing autophagy. PLoS One 9(6):e97957

    Article  PubMed Central  PubMed  Google Scholar 

  24. Dunn J, Qiu H, Kim S, Jjingo D, Hoffman R, Kim CW, Jang I, Son DJ, Kim D, Pan C, Fan Y, Jordan IK, Jo H (2014) Flow-dependent epigenetic DNA methylation regulates endothelial gene expression and atherosclerosis. J Clin Invest 124(7):3187–3199

    Article  CAS  PubMed Central  PubMed  Google Scholar 

  25. Hon GC, Song CX, Du T, Jin F, Selvaraj S, Lee AY, Yen CA, Ye Z, Mao SQ, Wang BA, Kuan S, Edsall LE, Zhao BS, Xu GL, He C, Ren B (2014) 5mC oxidation by Tet2 modulates enhancer activity and timing of Transcriptome reprogramming during differentiation. Mol Cell S1097–2765(14):681–689

    Google Scholar 

  26. Ko M, Huang Y, Jankowska AM, Pape UJ, Tahiliani M, Bandukwala HS, An J, Lamperti ED, Koh KP, Ganetzky R, Liu XS, Aravind L, Agarwal S, Maciejewski JP, Rao A (2010) Impaired hydroxylation of 5-methylcytosine in myeloid cancers with mutant TET2. Nature 468(7325):839–843

    Article  CAS  PubMed Central  PubMed  Google Scholar 

Download references

Acknowledgments

This research program was supported by grants from the National Natural Science Foundation of China (81370378) and the construct program of the key discipline in the Hunan province.

Conflict of interest

The authors have no conflict of interest.

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to Dangheng Wei.

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Li, G., Peng, J., Liu, Y. et al. Oxidized Low-Density Lipoprotein Inhibits THP-1-Derived Macrophage Autophagy via TET2 Down-regulation. Lipids 50, 177–183 (2015). https://doi.org/10.1007/s11745-014-3977-5

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s11745-014-3977-5

Keywords

Navigation