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Combined silencing of TGF-β2 and Snail genes inhibit epithelial-mesenchymal transition of retinal pigment epithelial cells under hypoxia

  • Basic Science
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Abstract

Background

The formation of scar-like fibrous tissue in age-related macular degeneration (AMD) is associated with hypoxia. Under hypoxia, retinal pigment epithelial (RPE) cells can secret more transforming growth factor-β2 (TGF-β2), which is determined to induce epithelial-mesenchymal transition (EMT) at certain concentrations. Whether hypoxia can induce EMT by stimulating RPE cell line secrets TGF-β2 or not remains unknown. To gain a better understanding of the signaling mechanisms of fibrosis in AMD under hypoxic conditions, we investigated EMT in retinal pigment epithelial (RPE) cells and the effect of TGF-β2 and Snail in this process.

Methods

Human RPE cell line (ARPE-19) was incubated with 5 % O2 for different periods of time. The expression of N-cadherin, α-smooth muscle actin (α-SMA), TGF-β2 , and Snail were determined by Western blot and real-time PCR. Cell proliferation was assessed by CCK8 kit. RNA interference was used for multi-gene silencing of TGF-β2 and Snail genes.

Results

N-cadherin was decreased and mesenchymal cell marker α-SMA was increased after the ARPE-19 cell line was incubated with 5 % O2. Meanwhile, the proliferation capability of the cell line was increased. TGF-β2 and Snail expression were increased in a time-dependent manner under hypoxia. After multi-silencing TGF-β2 and Snail genes, N-cadherin was increased and α-SMA was reduced. Meanwhile, the proliferation of the cell line was suppressed.

Conclusions

Under hypoxic conditions, RPE cells undergo EMT. Endogenic TGF-β2 and Snail are involved in this process. Furthermore, knockdown of both TGF-β2 and Snail inhibited EMT to a greater extent than knockdown of either gene individually.

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Authors and Affiliations

  1. Department of Ophthalmology, The First Affiliated Hospital of Harbin Medical University, 23 Youzheng Street, Nangang district, Harbin, 150001, Heilongjiang, Province, People’s Reepublic of China

    Zhuolei Feng, Ruishu Li, Huanqi Shi, Wenjiao Bi, Wenwen Hou & Xiaomei Zhang

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  1. Zhuolei Feng
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  2. Ruishu Li
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Correspondence to Xiaomei Zhang.

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Feng, Z., Li, R., Shi, H. et al. Combined silencing of TGF-β2 and Snail genes inhibit epithelial-mesenchymal transition of retinal pigment epithelial cells under hypoxia. Graefes Arch Clin Exp Ophthalmol 253, 875–884 (2015). https://doi.org/10.1007/s00417-014-2922-x

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  • DOI: https://doi.org/10.1007/s00417-014-2922-x

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