IS, characterized by rapid clinical signs of brain damage, ranks as the second leading global cause of death and the third in terms of disability [2]. The current clinical approach, centered on thrombolytic therapy for IS, faces a formidable challenge due to the lack of precisely defined targets and treatment mechanisms [1]. Pyroptosis, marked by cell membrane pore formation and pro-inflammatory cytokine release, emerges as an important player in the inflammatory response to IRI. The exploration of the intrinsic relationship between pyroptosis and IRI emerges as a crucial research avenue [6]. The urgency lies in unraveling this complex web of interactions to not only comprehend the pathogenesis of IS comprehensively but also to pave the way for targeted therapeutic strategies. This study, grounded in advanced RNA transcriptome analyses, seeks to bridge the gap in our understanding by elucidating the connections between pyroptosis, IRI, and the dynamic expression of RNA.
The comparison of MCAO patients and controls reveals a notable enrichment of genes in immune response pathways like IL1 and megakaryocytes signaling, IL18 signaling pathway, and Nfkb survival signaling (Fig. 6). This emphasizes the crucial involvement of immune cells in the complex molecular events following IRI [28]. Besides, our comparative analysis unveiled the double-strand break repair pathway, DNA replication pathway and cell cycle pathway have been extensively documented in the MCAO samples. The results showcase the consistency between our findings and previous research on the unexpected effects of DNA damage on IRI [9, 29]. Additionally, our study introduces innovative perspectives by uncovering the involvement of CD22-mediated BCR regulation and TP53 targets apoptotic in the IRI-induced pyroptosis process. These novel pathways offer insights into potential mechanisms underlying pyroptosis post-IRI.
Our study identified 25 key genes associated with pyroptosis in the context of IRI. Employing logistic modeling and SVM analyses, we strategically focused on four hub genes—WISP2, MELK, SDF2L1, and AURKB—as central players orchestrating the expression landscape of MCAO. WISP2, an adipokine known for its role in pro-inflammatory responses, emerged as a central player in modulating the inflammatory cascade in pyroptosis (30). Importantly, its anti-inflammatory properties align seamlessly with pathways governing immune responses and tissue repair (31). This dual role positions WISP2 as a critical regulator in the intricate network of pyroptotic events, making it a noteworthy focus of our study. MELK, a key regulator of the cell cycle, was identified as a significant influencer of cell survival dynamics in the context of pyroptosis (32). Its role in shaping cell cycle regulation connects with broader pathways governing cellular fate after IRI (33). This connection highlights MELK as a key player not only in pyroptotic processes but also in the broader landscape of cellular responses to ischemic insult, further emphasizing its relevance in our study. The study detailed the analysis of WISP2 and MELK in pyroptotic mechanisms. The consistency of our findings with existing literature further supports the robustness and reliability of our study, contributing valuable insights to the field and paving the way for potential therapeutic interventions in IRI-induced pyroptosis.
SDF2L1, linked to endoplasmic reticulum stress, influences cellular responses to ischemic insult (34). AURKB is a crucial regulator of cell division that influence cellular responses to pyroptosis (35–36). The identification of SDF2L1 and AURKB as key regulators enriches our understanding of their specific roles in IRI-induced pyroptosis. Their association with distinct biological pathways underscores their significance as potential therapeutic targets, emphasizing their intricate contributions to molecular events governing pyroptosis post-IRI injury. Upon validating the roles of SDF2L1 and AURKB in the MCAO rat model, our study makes a significant contribution by explicitly establishing their connections with IRI. This marks a pivotal revelation, as our research is the first to uncover the intricate relationship between these two genes and IRI. The identification of SDF2L1 and AURKB as contributors to the IRI landscape underscores their importance in understanding the pathophysiology of IRI-induced pyroptosis. This discovery holds particular value as it represents a novel finding and enhances the broader understanding of the molecular events underlying IRI.
Leukostasis, infiltration of neutrophils and macrophages, and activation of complements and microglial cells occur in patients and animal models with IRI [9]. In this study, the rising level of inflammatory cytokines and chemokines, including NF-kB pathway, IL18 pathway, and IL1 pathway (Fig. 7), were detected in MCAO, indicating a critical role of inflammation in IRI. WISP2, potentially pro-inflammatory, might influence pyroptosis post-IRI considering its link to the immune microenvironment [30]. Moreover, the infiltration of dendritic cells and natural killer cells were positively correlated with SDF2L1 expression in high and low IRI risk groups, respectively. The result implicates the role of endoplasmic reticulum stress responses in shaping the immune microenvironment during pyroptotic events. These findings collectively emphasize the multifaceted nature of the immune response in the context of IRI, implicating various cellular components and signaling pathways.
Our study not only revealed transcriptome signatures linked to pyroptosis in IRI-induced injury but also crafted a diagnostic model for MCAO. This model, built on four pivotal pyroptosis-associated genes—WISP2, MELK, SDF2L1, and AURKB—showed a strong discriminatory ability to distinguish MCAO cases from controls. Using logistic regression, we pinpointed these genes as crucial contributors to the predictive accuracy of our model. Integrating these genes into a diagnostic tool facilitates efficient risk stratification, aiding clinicians in identifying individuals at higher risk of adverse outcomes post-MCAO. Categorizing MCAO patients into high and low-risk groups using our diagnostic model revealed significant changes in key biological pathways, including attachment and entry, apoptosis CDKN2A downregulation, RUNX1 regulates transcription, and Nectin/Necl trans heterodimerization, seen in both groups. These findings suggest a potential link between risk stratification via our diagnostic model and dysregulation of these pathways. The observed pathway variations in high and low-risk groups emphasize the clinical relevance of our diagnostic model. While promising, future studies should validate its clinical utility in larger patient cohorts and explore potential therapeutic interventions based on the identified risk groups.
While our study provides insights into the transcriptome dynamics associated with pyroptosis in IRI-induced injury, several limitations should be acknowledged. Firstly, three public RNA transcriptome datasets of patients with MCAO were collected from public datasets. More research efforts should prioritize the collection of larger and more varied datasets to enhance the robustness and generalizability of our findings. Furthermore, the current study primarily focused on gene expression changes. The biological regulatory mechanisms of pyroptosis such as epigenetics and post-translational modifications could also participate in the IRI process. Future investigations should delve into the epigenetic landscape and protein-level alterations to unravel the complete molecular picture associated with pyroptosis in IRI induced injury.
In conclusion, our analysis depicted the transcription dynamics of IS pathogenesis and explored the potential molecular targets for IRI. By unveiling essential insights underlying MCAO and constructing a diagnostic model, we identified the specific mechanisms and molecular targets for IRI, especially those associated with DNA replication and immune response pathways, which warrant meticulous validation in subsequent research endeavors. These findings contribute to the ongoing efforts in refining IS therapeutic strategies, offering a foundation for more targeted and effective interventions.