LINE-1 retrotransposition events regulate gene expression after X-ray irradiation.

Area of Science:

• Genomics
• Molecular Biology
• Cellular Biology

Background:

• Long interspersed nuclear element-1 (LINE-1) are mobile genetic elements that transpose via RNA intermediates.
• LINE-1 integration involves target-primed reverse transcription (TPRT), inducing DNA double-strand breaks (DSBs).
• X-rays are known inducers of DNA damage.

Purpose of the Study:

• To investigate the impact of LINE-1 de novo retrotransposition on gene expression after X-ray irradiation.
• To evaluate the role of LINE-1 in the DNA damage response pathway in human endothelial cells.

Main Methods:

• Stable transfection of EA.hy926 human endothelial cells with LINE-1.
• X-ray irradiation (5 Gy) of transfected and wild-type (WT) cells.
• Analysis of gene expression using reverse transcription-polymerase chain reaction (RT-PCR).
• Quantification of phosphorylated p53 and γ-histone H2AX protein levels.

Main Results:

• EA.hy926 cells with LINE-1 showed rapid upregulation of phosphorylated p53 protein post-irradiation (15 min).
• Elevated γ-histone H2AX protein expression was observed in LINE-1 cells earlier (15 min) than in WT cells.
• LINE-1 retrotransposition events appear to modulate the kinetics of DNA damage response markers.

Conclusions:

• LINE-1 retrotransposition influences gene expression patterns in human endothelial cells following X-ray irradiation.
• LINE-1 elements may play a role in regulating the cellular response to DNA damage.