Functional Network of the Long Non-coding RNA Growth Arrest-Specific Transcript 5 and Its Interacting Proteins in Senescence.

Siqi Wang,Baowei Liu,Shengwei Ke,Wen Liu,Yao-Hui He,Xiaoyuan Song,Duo Zhang,Huawei Mu,Yueming Wu

doi:10.3389/fgene.2021.615340

Abstract

Increasing studies show that long non-coding RNAs (lncRNAs) play essential roles in various fundamental biological processes. Long non-coding RNA growth arrest-specific transcript 5 (GAS5) showed differential expressions between young and old mouse brains in our previous RNA-Seq data, suggesting its potential role in senescence and brain aging. Examination using quantitative reverse transcription-polymerase chain reaction revealed that GAS5 had a significantly higher expression level in the old mouse brain hippocampus region than the young one. Cellular fractionation using hippocampus-derived HT22 cell line confirmed its nucleoplasm and cytoplasm subcellular localization. Overexpression or knockdown of GAS5 in HT22 cell line revealed that GAS5 inhibits cell cycle progression and promotes cell apoptosis. RNA-Seq analysis of GAS5-knockdown HT22 cells identified differentially expressed genes related to cell proliferation (e.g., DNA replication and nucleosome assembly biological processes). RNA pull-down assay using mouse brain hippocampus tissues showed that potential GAS5 interacting proteins could be enriched into several Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, and some of them are involved in senescence-associated diseases such as Parkinson’s and Alzheimer’s diseases. These results contribute to understand better the underlying functional network of GAS5 and its interacting proteins in senescence at brain tissue and brain-derived cell line levels. Our study may also provide a reference for developing diagnostic and clinic biomarkers of GAS5 in senescence and brain aging.

Highlights

Cellular senescence refers to the cessation of normal cell division under various conditions such as cellular stress and DNA damage
Our result suggested that growth arrestspecific transcript 5 (GAS5) may participate in senescence in the brain, as it showed higher expression in the aging mouse brain and had a brain regionspecific expression pattern
As the research on GAS5 going further, more and more studies have shown that long non-coding RNAs (lncRNAs) GAS5 is low-expressed in most of the tumor samples, such as glioma, non-small cell lung cancer, breast carcinoma, etc

Summary

Introduction

Cellular senescence refers to the cessation of normal cell division under various conditions such as cellular stress and DNA damage. Studies have shown that nuclear fiber layer forms can be used as an identifier of phenotypic senescent cells (Raz et al, 2008), at the same time, mitochondrial DNA damage causes mitochondrial dysfunction and upregulation of reactive oxygen species, which may be induced by telomere dysfunction caused cellular senescence (Passos et al, 2007). Higher oxidative status caused by mitochondrial dysfunction was reported to contribute to senescence acceleration and the age-dependent alterations in cell structure and function (Hosokawa, 2002, 2004). Studies showed that the expression level of glial fibrillary acidic protein (GFAP), a protein marker of astrocytes in the brain, was upregulated significantly in old senescence-acceleratedprone 8 mice, indicating an important role of GFAP in the age-related deficits in learning and memory (Wu et al, 2005). Upregulation of senescence-associated proteins p16 and p21 was found in granule cells of the dentate gyrus in the irradiation-induced mouse hippocampus, showing a similar senescence phenotype (Cheng et al, 2017)

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