Modulation of ferroptosis via YY1-SLC7A11 axis in hepatic ischemia-reperfusion injury pathogenesis

Abstract

YY1 is a crucial transcription factor and plays significant roles in biological processes. However, the mechanisms of YY1 action in ischemia-reperfusion injury and its regulatory role in ferroptosis have not been extensively studied. This study aims to elucidate the molecular mechanism by which NEDD4L-mediated degradation of YY1 through ubiquitination suppresses SLC7A11 transcription, leading to the promotion of cellular ferroptosis and exacerbation of hepatic ischemia-reperfusion injury (IRI), via the integration of multiple omics sequencing datasets. An IRI-I/R mouse model is established, followed by proteomic sequencing to identify proteins that are differentially expressed during IRI. The altered expression of YY1 is validated, and in vivo and in vitro experiments are used to assess its impact on IRI damage. The E3 ligase NEDD4L, which regulates YY1 ubiquitination, is identified and validated via the UbiBrowser 2.0 database. The ubiquitination types of YY1 and its sites are screened and confirmed through in vitro experiments. Transcriptional sequencing of YY1-overexpressing cell lines is conducted to analyze the involvement of the downstream transcription factor SLC7A11 in IRI, followed by validation of its regulatory role. The results show that YY1 is downregulated in liver tissues during IRI and is expressed primarily in liver cells. YY1 overexpression alleviates liver tissue and liver cell IRI both in vitro and in vivo. Upregulation of E3 ligase expression during IRI promotes the K63-linked ubiquitination of YY1 at the K339 site, leading to proteasomal degradation of YY1. RNA-seq analysis and experimental validation demonstrate that YY1 suppresses IRI-induced ferroptosis via the transcriptional regulation of downstream target genes. YY1 positively regulates SLC7A11 transcription, inhibits IRI-induced ferroptosis and ameliorates liver injury. In summary, the E3 ubiquitin ligase NEDD4L facilitates YY1 protein degradation through ubiquitination, suppressing the transcription of the ferroptosis inhibitor SLC7A11, thus promoting IRI-related ferroptosis and exacerbating liver injury.

1. Introduction

Ischemia-reperfusion injury (IRI) is a significant pathological process present in diseases such as myocardial infarction, stroke, and organ transplantation [1–3]. During the occurrence and development of IRI, cells are subjected to various types of damage, including oxidative stress, inflammatory reactions, and apoptosis. Recent studies have identified ferroptosis as a novel form of cell death that plays a crucial role in IRI, offering new insights into the study of this disease [4–6]. Therefore, a thorough investigation of the molecular mechanisms of IRI is of paramount importance for unraveling the essence of disease occurrence and discovering new therapeutic strategies.

YY1 is a protein that serves as a crucial transcription factor and plays significant roles in biological processes such as cell proliferation, differentiation, and death [7–9]. However, the mechanisms of YY1 action in IRI and its regulatory role in ferroptosis have not been extensively studied [10]. Studies have indicated that downregulation of YY1 expression during IRI may be closely associated with the occurrence of ferroptosis [11–13]. Therefore, a more detailed and in-depth exploration of the role of YY1 in IRI is crucial for understanding the pathogenesis of IRI.

The E3 ubiquitin ligase NEDD4L is an important regulator of ubiquitination and is involved in the degradation and maintenance of cellular proteins through ubiquitination processes [14–16]. Recent studies have revealed the critical role of NEDD4L in IRI, particularly its association with cellular ferroptosis [17,18]. Specifically, YY1, a key transcription factor, is regulated by NEDD4L at the protein level, influencing the occurrence of ferroptosis during IRI. Therefore, investigating the specific mechanisms of NEDD4L in IRI not only aids in a deeper understanding of crucial aspects of the pathophysiology of IRI but also provides a new research perspective for the development of therapeutic strategies for this disease.