Extremely low frequency-pulsed electromagnetic fields affect proangiogenic-related gene expression in retinal pigment epithelial cells

Document Type: Original Article

Authors

1 Stem Cell Research Center, Golestan University of Medical Sciences, Gorgan, Iran

2 Ischemic Disorders Research Center, Golestan University of Medical Sciences, Gorgan, Iran

3 Department of Clinical Biochemistry and Genetics, Molecular and Cell Biology Research Center, Faculty of Medicine, Mazandaran University of Medical Sciences, Sari, Iran

4 Tissue Engineering Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran

5 Immunology Department, Babol University of Medical Sciences, Babol, Iran

6 Medical Cellular and Molecular Research Center, Golestan University of Medical Sciences, Gorgan, Iran

7 Department of Medical Biotechnology, School of Advanced Technologies in Medicine, Golestan University of Medical Sciences, Gorgan, Iran

Abstract

Objective(s): It is known that extremely low frequency-pulsed electromagnetic fields (ELF-PEMF) influence multiple cellular and molecular processes. Retinal pigment epithelial (RPE) cells have a significant part in the emergence and pathophysiology of several ocular disorders, such as neovascularization. This study assessed the impact of ELF-PEMF on the proangiogenic features of RPE cells.
Materials and Methods: Primary cultured RPE cells were treated with ELF-PEMF (50 Hz) for three days. Using ELISA assay, we evaluated the effects of treatment on RPE cell proliferation and apoptosis. Also, RT-PCR was used to determine the gene expression of proangiogenic factors, such as matrix metalloproteinase-2 (MMP-2), MMP-9, vascular endothelial growth factors receptor 2 (VEGFR-2), hypoxia-inducible factor 1 (HIF-1α), VEGFA, cathepsin D, connective tissue growth factor (CTGF), E2F3, tissue inhibitors of metalloproteinases 1 (TIMP-1), and TIMP-2.
Results: No noticeable changes were observed in cell proliferation and cell death of ELF-PEMF-exposed RPE cells, while transcript levels of proangiogenic genes (HIF-1α, VEGFA, VEGFR-2, CTGF, cathepsin D, TIMP-1, E2F3, MMP-2, and MMP-9) increased significantly.
Conclusion: RPE cells are important for homeostasis of the retina. ELF-PEMF increased the gene expression of proangiogenic factors in RPE cells, which highlights concerns about the impact of this treatment on human health.

Keywords

Main Subjects


1. Ma Q, Deng P, Zhu G, Liu C, Zhang L, Zhou Z, et al. Extremely low-frequency electromagnetic fields affect transcript levels of neuronal differentiation-related genes in embryonic neural stem cells. PloS one 2014; 9:e90041.
2. Kim H-J, Jung J, Park J-H, Kim J-H, Ko K-N, Kim C-W. Extremely low-frequency electromagnetic fields induce neural differentiation in bone marrow derived mesenchymal stem cells. Exp Biol Med (Maywood) 2013; 238:923-931.
3. Ross CL, Siriwardane M, Almeida-Porada G, Porada CD, Brink P, Christ GJ, et al. The effect of low-frequency electromagnetic field on human bone marrow stem/progenitor cell differentiation. Stem Cell Res 2015; 15:96-108.
4. Hong WX, Hu MS, Esquivel M, Liang GY, Rennert RC, McArdle A, et al. The role of hypoxia-inducible factor in wound healing. Adv Wound Care  2014; 3:390-399.
5. Katoh M. Therapeutics targeting angiogenesis: genetics and epigenetics, extracellular miRNAs and signaling networks. Int J Mol Med 2013; 32:763-767.
6. Fuhrmann S, Zou C, Levine EM. Retinal pigment epithelium development, plasticity, and tissue homeostasis. Exp Eye Res 2014; 123:141-150.
7. Sene A, Chin-Yee D, Apte RS. Seeing through VEGF: innate and adaptive immunity in pathological angiogenesis in the eye. Trends Mol Med 2015; 21:43-51.
8. Ma IT, McConaghy S, Namachivayam K, Halloran BA, Kurundkar AR, MohanKumar K, et al. VEGF mRNA and protein concentrations in the developing human eye. Pediatr Res. 2015;77:500-505.
9. Ranjbar M, Brinkmann MP, Tura A, Rudolf M, Miura Y, Grisanti S. Ranibizumab interacts with the VEGF-A/VEGFR-2 signaling pathway in human RPE cells at different levels. Cytokine 2016; 83:210-216.
10. Pescosolido N, Giannotti R, Buomprisco G. Metalloproteinases and eye diseases. Biomedicine & Aging Pathology 2013; 3:97-105.
11. Sonoda S, Nagineni CN, Kitamura M, Spee C, Kannan R, Hinton DR. Ceramide inhibits connective tissue growth factor expression by human retinal pigment epithelial cells. Cytokine 2014; 68:137-140.
12. Klettner A, Kauppinen A, Blasiak J, Roider J, Salminen A, Kaarniranta K. Cellular and molecular mechanisms of age-related macular degeneration: from impaired autophagy to neovascularization. Int J Biochem Cell Biol 2013; 45:1457-1467.
13. Bagheri A, Soheili Z-S, Ahmadieh H, Samiei S, Sheibani N, Astaneh SD, et al. Simultaneous application of bevacizumab and anti-CTGF antibody effectively suppresses proangiogenic and profibrotic factors in human RPE cells. Mol Vis 2015; 21:378-390.
14. Sun D, Nakao S, Xie F, Zandi S, Bagheri A, Kanavi MR, et al. Molecular imaging reveals elevated VEGFR-2 expression in retinal capillaries in diabetes: a novel biomarker for early diagnosis. T FASEB J 2014; 28:3942-3951.
15. Crawford TN, Alfaro I, Kerrison JB, Jablon EP. Diabetic retinopathy and angiogenesis. Curr Diabetes Rev 2009; 5:8-13.
16. Shibuya M. Invited Review: VEGF-VEGFR Signals in Health and Disease. Biomol Ther (Seoul). 2014; 22:1-9.
17. VEGF A, as a Biomarker PBI. Role of the VEGF/VEGFR axis in cancer biology and therapy. Adv Cancer Res 2012; 114:237.
18. Wheler JJ, Janku F, Naing A, Li Y, Stephen B, Zinner R, et al. TP53 Alterations correlate with response to VEGF/VEGFR inhibitors: implications for targeted therapeutics. Mol Cancer Ther 2016; 15:2475-2485
19. Klaassen I, van Geest RJ, Kuiper EJ, van Noorden CJ, Schlingemann RO. The role of CTGF in diabetic retinopathy. Exp Eye Res 2015; 133:37-48.
20. Delhiwala KS, Vadakkal IP, Mulay K, Khetan V, Wick MR, editors. Retinoblastoma: An update. Semin Diagn Pathol; 2016: Elsevier.
21. Akrami H,  Soheili Z, Khalooghi K, Ahmadieh H, Rezaie-Kanavi M, Samiei S, et al. Retinal pigment epithelium culture; a potential source of retinal stem cells. J Ophthalmic Vis Res. 2009; 4: 134–141.
22. Mohammadian A, Soheili Z-S, Jalal R, Bagheri A, Samiei S, Ahmadieh H. Investigation of melanogenic factors gene expression in human adult and neonate retinal pigment epithelium cell cultures. Journal of Cell and Molecular Research 2015; 7:76-85.
23. Maziarz A, Kocan B, Bester M, Budzik S, Cholewa M, Ochiya T, et al. How electromagnetic fields can influence adult stem cells: positive and negative impacts. Stem Cell Res Ther 2016;1-12.
24. Zhou Y, Zhang Y, Shi K, Wang C. Body mass index and risk of diabetic retinopathy: A meta-analysis and systematic review. Medicine (Baltimore) 2017;96:e6754.
25. Wong WL, Su X, Li X, Cheung CMG, Klein R, Cheng C-Y, et al. Global prevalence of age-related macular degeneration and disease burden projection for 2020 and 2040: a systematic review and meta-analysis. Lancet Glob Health 2014; 2:e106-e116.
26. Van Geest RJ, Klaassen I, Lesnik-Oberstein SY, Tan HS, Mura M, Goldschmeding R, et al. Vitreous TIMP-1 levels associate with neovascularization and TGF-β2 levels but not with fibrosis in the clinical course of proliferative diabetic retinopathy. J Cell Commun Signal 2013; 7:1-9.
27. Miller JW, Le Couter J, Strauss EC, Ferrara N. Vascular endothelial growth factor a in intraocular vascular disease. Ophthalmology 2013; 120:106-114.
28. Niu G, Chen X. Vascular endothelial growth factor as an anti-angiogenic target for cancer therapy. Curr Drug Targets. 2010; 11:1000-1017.
29. Kuiper EJ, Hughes JM, Van Geest RJ, Vogels IM, Goldschmeding R, Van Noorden CJ, et al. Effect of VEGF-A on expression of profibrotic growth factor and extracellular matrix genes in the retina. Invest Ophthalmol Vis Sci 2007; 48:4267-4276.
30. Shibuya M, Okamoto H, Nozawa T, Utsumi J, Reddy VN, Echizen H, et al. Proteomic and transcriptomic analyses of retinal pigment epithelial cells exposed to REF-1/TFPI-2. Invest Ophthalmol Vis Sci. 2007; 48:516-521.
31. Usui Y, Westenskow PD, Murinello S, Dorrell MI, Scheppke L, Bucher F, et al. Angiogenesis and eye disease. Annu Rev Vis Sci 2015; 1:155-184.