Poster abstracts
Poster number 122 submitted by Sydney Rudolph
Role of the lncRNA MEG9 in Vascular Endothelial Cells in Response to Stress
Sydney Rudolph (Center for Molecular Medicine and Genetics, Wayne State University, Detroit, MI), Miguel Nieto-Hernandez (Center for Molecular Medicine and Genetics,Wayne State University, Detroit, MI), Chayan Bhattacharya (Center for Molecular Medicine and Genetics, Wayne State University, Detroit, MI), Sudarshan Anand (Knight Cancer Institute, Oregon Health and Science University, Portland, OR), Cristina Espinosa-Diez (Center for Molecular Medicine and Genetics,Wayne State University, Detroit, MI)
Abstract:
Cellular stress of vascular endothelial cells can lead to a dysregulation of normal cellular functions, including a disruption in angiogenesis and vascular remodeling. Long non-coding RNAs (lncRNAs) are key regulators of vascular function that control gene expression through different mechanisms, including chromatin remodeling, gene splicing, and translation control, enabling endothelial cells to respond to environmental changes. The lncRNA, Maternally Expressed Gene 9 (MEG9), is encoded in the DLK1-DIO3 non-coding RNA cluster on Chromosome 14 and shows an increased expression in endothelial cells under stress. Our preliminary data illustrate that genotoxic stressors such as radiation etoposide, increase MEG9 expression, while exposure to vascular growth factors inhibits it. We hypothesize that the MEG9 could be part of vascular endothelial cells' adaptive stress-induced protective mechanism. We further tested MEG9 responses to oxidative stress by treating Human umbilical Vein Endothelial Cells (HUVECs) with Hydrogen Peroxide (H2O2) and Doxorubicin. We validated that MEG9 expression was upregulated in both instances compared to the non-treated control. To better understand the role of MEG9 in endothelial cells, we performed MEG9 loss of function using antisense oligonucleotide inhibitors (GapmeRs), specifically designed to knock down MEG9 expression and validate by RT-qPCR. We studied angiogenesis by performing tube formation assay, apoptosis with live/dead staining, and DNA damage by analyzing H2AX foci formation with and without exposure to stressors. Cells with MEG9 deficiency showed higher rates of cell death, and H2AX foci count, further enhanced by stress. Furthermore, loss of MEG9 decreased angiogenesis. In conclusion, our data indicate that loss of MEG9 impaired endothelial function and the ability to withstand cellular stressors. Therefore, MEG9 expression potentially is a compensatory adaptive protective mechanism in HUVECs in response to acute stress. In future studies, we will test the protective role of MEG9 in vitro and in vivo, together with its downstream regulators.
References:
DNA damage-induced lncRNA MEG9 impacts angiogenesis
Eugenia Fraile-Bethencourt, Sokchea Khou, RaeAnna Wilson, Adrian Baris, Rebecca Ruhl, Cristina Espinosa-Diez, Sudarshan Anand
bioRxiv 2022.12.07.519382; doi: https://doi.org/10.1101/2022.12.07.519382
Keywords: LncRNAs, Vascular Biology, Apoptosis