Dysregulation of a lncRNA within the TNFRSF10A locus activates cell death pathways

Abstract

AbstractTNFRSF10A (tumor necrosis factor receptor superfamily member 10A)encodes a cell surface receptor protein involved in apoptotic, necroptotic, and inflammatory pathways. Dysregulation ofTNFRSF10Ahas been implicated in sensitization to apoptosis and to the development of multiple diseases, yet little is known of theAC100861.1long noncoding RNA (lncRNA) that lies head-to-head withTNFRSF10A. Given its genomic positioning, we sought to investigate the function ofAC100861.1, focusing on its potential relationship withTNFRSF10Aand the role it may play in death receptor signaling. Using knockdown and overexpression strategies, we probed cell viability and examined transcript and protein-level changes in key genes involved in apoptosis, necroptosis, and inflammation. Decreased cell viability was observed uponTNFRSF10Aoverexpression, regardless of whether the cells were subjected to the chemical stressor tunicamycin. Similarly, overexpression ofAC100861.1led to increased cell death, with a further increase observed under conditions of cellular stress. Knockdown ofTNFRSF10Aincreased cell death only when the cells were stressed, andAC100861.1knockdown exhibited no effect on cell death. Neither knockdown nor overexpression of either of these genes greatly affected the expression of the other. ManipulatingAC100861.1, however, led to marked changes in the expression of genes involved in necroptosis and inflammatory cell-signaling pathways. Additionally, RNA fluorescence in situ hybridization (RNA-FISH) revealed that theAC100861.1transcript is localized primarily to the cytoplasm. Together, these data suggest thatAC100861.1may have a role in regulating necroptotic and inflammatory signaling pathways and that this function is separate from changes inTNFRSF10Aexpression. Given the importance of this genomic locus for cell survival, these data provide insight into the function of a poorly understood lncRNA with potential implications regarding disease pathology and treatment.