Functional genomics study of protein inhibitor of activated STAT1 in mouse hippocampal neuronal cells revealed by RNA sequencing

Abstract

Protein inhibitor of activated STAT1 (PIAS1), a small ubiquitin-like modifier (SUMO) E3 ligase, was considered to be an inhibitor of STAT1 by inhibiting the DNA-binding activity of STAT1 and blocking STAT1-mediated gene transcription in response to cytokine stimulation. PIAS1 has been determined to be involved in modulating several biological processes such as cell proliferation, DNA damage responses, and inflammatory responses, both in vivo and in vitro . However, the role played by PIAS1 in regulating neurodegenerative diseases, including Alzheimer’s disease (AD), has not been determined. In our study, significantly different expression levels of PIAS1 between normal controls and AD patients were detected in four regions of the human brain. Based on a functional analysis of Pias1 in undifferentiated mouse hippocampal neuronal HT-22 cells, we observed that the expression levels of several AD marker genes could be inhibited by Pias1 overexpression. Moreover, the proliferation ability of HT-22 cells could be promoted by the overexpression of Pias1 . Furthermore, we performed RNA sequencing (RNA-seq) to evaluate and quantify the gene expression profiles in response to Pias1 overexpression in HT-22 cells. As a result, 285 significantly dysregulated genes, including 79 upregulated genes and 206 downregulated genes, were identified by the comparison of Pias1 /+ cells with WT cells. Among these genes, five overlapping genes, including early growth response 1 ( Egr1 ), early growth response 2 ( Egr2 ), early growth response 3 ( Egr3 ), FBJ osteosarcoma oncogene ( Fos ) and fos-like antigen 1 ( Fosl1 ), were identified by comparison of the transcription factor binding site (TFBS) prediction results for STAT1, whose expression was evaluated by qPCR. Three cell cycle inhibitors, p53, p18 and p21, were significantly downregulated with the overexpression of Pias1 . Analysis of functional enrichment and expression levels showed that basic region leucine zipper domain-containing transcription factors including zinc finger C2H2 (zf-C2H2), homeobox and basic/helix-loop-helix (bHLH) in several signaling pathways were significantly involved in PIAS1 regulation in HT-22 cells. A reconstructed regulatory network under PIAS1 overexpression demonstrated that there were 43 related proteins, notably Nr3c2, that directly interacted with PIAS1.

Blood and brain transcriptome analysis reveals APOE genotype-mediated and immune-related pathways involved in Alzheimer disease

“…Our study showed that FOSL1 and TRIP10 were among the genes enriched in the TNFA via the NFKB pathway, and their expression was associated with ICAM-1. TRIP10 was previously included in an AD network derived from multi-omic integration [59] and FOSL-1 was identified in conjunction with PIAS1, a protein associated with AD and inflammatory response [60]. We identified VASP and C4B in an APOE genotype-specific co-expressed gene network in the brain that was reproduced in the blood, and the expression of these genes was significantly associated with levels of multiple vascular damage proteins.…”

Blood and Brain Transcriptome Analysis Reveals APOE Genotype-mediated and Immune-related Pathways Involved in Alzheimer Disease

“…Our study showed that FOSL1 and TRIP10 were among the genes enriched in the TNFA via NFKB pathway, and their expression was associated with ICAM-1. TRIP10 was previously included in an AD network derived from multi-omic integration [54] and FOSL-1 was identified in conjunction with PIAS1, a protein associated with AD and inflammatory response [55]. We identified VASP and C4B in an APOE genotype-specific co-expressed gene network in brain that was reproduced in blood, and expression of these genes was significantly associated with levels of multiple vascular damage proteins.…”

The Emerging Roles of E3 Ligases and DUBs in Neurodegenerative Diseases

“…In this study, the authors constructed a regulatory network for PIAS1 overexpression, including nuclear receptor subfamily 3 group C member 2 (NR3C2), which directly interacts with PIAS1. However, further studies on these downstream targets are necessary [ 84 ].…”